diff --git a/.changeset/quick-dingos-decide.md b/.changeset/quick-dingos-decide.md
new file mode 100644
index 00000000000..d31f3f45366
--- /dev/null
+++ b/.changeset/quick-dingos-decide.md
@@ -0,0 +1,5 @@
+---
+'@tanstack/router-plugin': patch
+---
+
+Improve route code-splitting build performance by parsing each reference route once for grouping detection, shared-binding analysis, and compilation.
diff --git a/packages/router-plugin/src/core/code-splitter/compilers.ts b/packages/router-plugin/src/core/code-splitter/compilers.ts
index 89cdae41add..11874b2f309 100644
--- a/packages/router-plugin/src/core/code-splitter/compilers.ts
+++ b/packages/router-plugin/src/core/code-splitter/compilers.ts
@@ -28,7 +28,11 @@ import type {
   CodeSplitCompilerPlugin,
   CompileCodeSplitReferenceRouteOptions,
 } from './plugins'
-import type { GeneratorResult, ParseAstOptions } from '@tanstack/router-utils'
+import type {
+  GeneratorResult,
+  ParseAstOptions,
+  ParseAstResult,
+} from '@tanstack/router-utils'
 import type { CodeSplitGroupings, SplitRouteIdentNodes } from '../constants'
 import type { SplitNodeMeta } from './types'
 
@@ -153,8 +157,14 @@ export function computeSharedBindings(opts: {
   filename?: string
   codeSplitGroupings: CodeSplitGroupings
 }): Set<string> {
-  const ast = parseAst(opts)
+  return computeSharedBindingsFromAst(parseAst(opts), opts.codeSplitGroupings)
+}
 
+/** Internal analysis of the original, unmodified reference AST. */
+export function computeSharedBindingsFromAst(
+  ast: t.File,
+  codeSplitGroupings: CodeSplitGroupings,
+): Set<string> {
   // Early bailout: collect all module-level locally-declared binding names.
   // This is a cheap loop over program.body (no traversal). If the file has
   // no local bindings (aside from `Route`), nothing can be shared — skip
@@ -173,9 +183,7 @@ export function computeSharedBindings(opts: {
   }
 
   function findIndexForSplitNode(str: string) {
-    return opts.codeSplitGroupings.findIndex((group) =>
-      group.includes(str as any),
-    )
+    return codeSplitGroupings.findIndex((group) => group.includes(str as any))
   }
 
   // Find the route options object — needs babel.traverse for scope resolution
@@ -361,14 +369,22 @@ function removeSharedDeclarations(ast: t.File, sharedBindings: Set<string>) {
   })
 }
 
+type ReferenceCompilerOptions = ParseAstOptions &
+  CompileCodeSplitReferenceRouteOptions & {
+    compilerPlugins?: Array<CodeSplitCompilerPlugin>
+  }
+
 export function compileCodeSplitReferenceRoute(
-  opts: ParseAstOptions &
-    CompileCodeSplitReferenceRouteOptions & {
-      compilerPlugins?: Array<CodeSplitCompilerPlugin>
-    },
+  opts: ReferenceCompilerOptions,
 ): GeneratorResult | null {
-  const ast = parseAst(opts)
+  return compileCodeSplitReferenceRouteFromAst(parseAst(opts), opts)
+}
 
+/** Internal compiler: consumes the AST after grouping and shared-binding analysis. */
+export function compileCodeSplitReferenceRouteFromAst(
+  ast: ParseAstResult,
+  opts: ReferenceCompilerOptions,
+): GeneratorResult | null {
   const refIdents = findReferencedIdentifiers(ast)
 
   const knownExportedIdents = new Set<string>()
@@ -1395,8 +1411,13 @@ export function compileCodeSplitSharedRoute(
 export function detectCodeSplitGroupingsFromRoute(opts: ParseAstOptions): {
   groupings: CodeSplitGroupings | undefined
 } {
-  const ast = parseAst(opts)
+  return detectCodeSplitGroupingsFromAst(parseAst(opts))
+}
 
+/** Internal analysis of the original, unmodified reference AST. */
+export function detectCodeSplitGroupingsFromAst(ast: t.File): {
+  groupings: CodeSplitGroupings | undefined
+} {
   let codeSplitGroupings: CodeSplitGroupings | undefined = undefined
 
   babel.traverse(ast, {
diff --git a/packages/router-plugin/src/core/router-code-splitter-plugin.ts b/packages/router-plugin/src/core/router-code-splitter-plugin.ts
index f1f75d4f3c1..af5097b96de 100644
--- a/packages/router-plugin/src/core/router-code-splitter-plugin.ts
+++ b/packages/router-plugin/src/core/router-code-splitter-plugin.ts
@@ -4,14 +4,14 @@
  */
 
 import { fileURLToPath, pathToFileURL } from 'node:url'
-import { decodeIdentifier, logDiff } from '@tanstack/router-utils'
+import { decodeIdentifier, logDiff, parseAst } from '@tanstack/router-utils'
 import { getConfig, splitGroupingsSchema } from './config'
 import {
-  compileCodeSplitReferenceRoute,
+  compileCodeSplitReferenceRouteFromAst,
   compileCodeSplitSharedRoute,
   compileCodeSplitVirtualRoute,
-  computeSharedBindings,
-  detectCodeSplitGroupingsFromRoute,
+  computeSharedBindingsFromAst,
+  detectCodeSplitGroupingsFromAst,
 } from './code-splitter/compilers'
 import { getFrameworkHmrCompilerPlugins } from './code-splitter/plugins/framework-plugins'
 import {
@@ -134,10 +134,11 @@ export function createRouterCodeSplitterPlugin(
   ): UnpluginTransformResult => {
     if (debug) console.info('Compiling Route: ', id)
 
-    const fromCode = detectCodeSplitGroupingsFromRoute({
+    const ast = parseAst({
       code,
       filename: id,
     })
+    const fromCode = detectCodeSplitGroupingsFromAst(ast)
 
     if (fromCode.groupings !== undefined) {
       const res = splitGroupingsSchema.safeParse(fromCode.groupings)
@@ -168,19 +169,15 @@ export function createRouterCodeSplitterPlugin(
     const splitGroupings: CodeSplitGroupings =
       fromCode.groupings ?? pluginSplitBehavior ?? getGlobalCodeSplitGroupings()
 
-    // Compute shared bindings before compiling the reference route
-    const sharedBindings = computeSharedBindings({
-      code,
-      filename: id,
-      codeSplitGroupings: splitGroupings,
-    })
+    // Both analyses must finish before the reference compiler mutates this AST.
+    const sharedBindings = computeSharedBindingsFromAst(ast, splitGroupings)
     if (sharedBindings.size > 0) {
       sharedBindingsMap.set(id, sharedBindings)
     } else {
       sharedBindingsMap.delete(id)
     }
 
-    const compiledReferenceRoute = compileCodeSplitReferenceRoute({
+    const compiledReferenceRoute = compileCodeSplitReferenceRouteFromAst(ast, {
       code,
       codeSplitGroupings: splitGroupings,
       targetFramework: userConfig.target,
diff --git a/packages/router-plugin/tests/add-hmr.test.ts b/packages/router-plugin/tests/add-hmr.test.ts
index 98b3e61a5f9..999264153ed 100644
--- a/packages/router-plugin/tests/add-hmr.test.ts
+++ b/packages/router-plugin/tests/add-hmr.test.ts
@@ -1,8 +1,14 @@
 import { readFile, readdir } from 'node:fs/promises'
 import path from 'node:path'
 import { describe, expect, it } from 'vitest'
-
-import { compileCodeSplitReferenceRoute } from '../src/core/code-splitter/compilers'
+import { parseAst } from '@tanstack/router-utils'
+
+import {
+  compileCodeSplitReferenceRoute,
+  compileCodeSplitReferenceRouteFromAst,
+  computeSharedBindingsFromAst,
+  detectCodeSplitGroupingsFromAst,
+} from '../src/core/code-splitter/compilers'
 import { defaultCodeSplitGroupings } from '../src/core/constants'
 import { getFrameworkHmrCompilerPlugins } from '../src/core/code-splitter/plugins/framework-plugins'
 import { createRouteHmrStatement } from '../src/core/hmr'
@@ -14,6 +20,27 @@ function getFrameworkDir(framework: string) {
   return { files, snapshots }
 }
 
+function compileWithRootParity(
+  opts: Parameters<typeof compileCodeSplitReferenceRoute>[0],
+) {
+  const result = compileCodeSplitReferenceRoute(opts)
+  if (opts.filename.startsWith('createRootRoute')) {
+    // Reuse root snapshots for both paths, including WithContext/type arguments
+    // and the addHmr:false null-result path. Roots must never be extracted.
+    const ast = parseAst(opts)
+    expect(detectCodeSplitGroupingsFromAst(ast).groupings).toBeUndefined()
+    expect(
+      computeSharedBindingsFromAst(ast, opts.codeSplitGroupings).size,
+    ).toBe(0)
+    const parsedResult = compileCodeSplitReferenceRouteFromAst(ast, opts)
+    expect(parsedResult === null).toBe(result === null)
+    expect(parsedResult?.code).toBe(result?.code)
+    expect(parsedResult?.map).toEqual(result?.map)
+    return parsedResult
+  }
+  return result
+}
+
 describe('add-hmr works', () => {
   describe.each(frameworks)('FRAMEWORK=%s', async (framework) => {
     const dirs = getFrameworkDir(framework)
@@ -25,7 +52,7 @@ describe('add-hmr works', () => {
         const file = await readFile(path.join(dirs.files, filename))
         const code = file.toString()
 
-        const compileResult = compileCodeSplitReferenceRoute({
+        const compileResult = compileWithRootParity({
           code,
           filename,
           id: filename,
@@ -49,7 +76,7 @@ describe('add-hmr works', () => {
         const file = await readFile(path.join(dirs.files, filename))
         const code = file.toString()
 
-        const compileResult = compileCodeSplitReferenceRoute({
+        const compileResult = compileWithRootParity({
           code,
           filename,
           id: filename,
diff --git a/packages/router-plugin/tests/code-splitter.test.ts b/packages/router-plugin/tests/code-splitter.test.ts
index 967f102e4d4..1dcf4bda356 100644
--- a/packages/router-plugin/tests/code-splitter.test.ts
+++ b/packages/router-plugin/tests/code-splitter.test.ts
@@ -10,9 +10,13 @@ import {
   collectLocalBindingsFromStatement,
   collectModuleLevelRefsFromNode,
   compileCodeSplitReferenceRoute,
+  compileCodeSplitReferenceRouteFromAst,
   compileCodeSplitSharedRoute,
   compileCodeSplitVirtualRoute,
   computeSharedBindings,
+  computeSharedBindingsFromAst,
+  detectCodeSplitGroupingsFromAst,
+  detectCodeSplitGroupingsFromRoute,
   expandDestructuredDeclarations,
   expandSharedDestructuredDeclarators,
   expandTransitively,
@@ -76,7 +80,7 @@ describe('code-splitter works', () => {
               codeSplitGroupings: grouping,
             })
 
-            const compileResult = compileCodeSplitReferenceRoute({
+            const opts = {
               code,
               filename,
               id: filename,
@@ -85,9 +89,32 @@ describe('code-splitter works', () => {
               targetFramework: framework,
               sharedBindings:
                 sharedBindings.size > 0 ? sharedBindings : undefined,
+            }
+            const compileResult = compileCodeSplitReferenceRoute(opts)
+
+            // Exercise the plugin's parse-once ordering across the entire
+            // snapshot matrix, including scope-sensitive shared extraction.
+            const ast = parseAst({ code, filename })
+            expect(detectCodeSplitGroupingsFromAst(ast)).toEqual(
+              detectCodeSplitGroupingsFromRoute({ code, filename }),
+            )
+            const parsedSharedBindings = computeSharedBindingsFromAst(
+              ast,
+              grouping,
+            )
+            expect(parsedSharedBindings).toEqual(sharedBindings)
+            const parsedResult = compileCodeSplitReferenceRouteFromAst(ast, {
+              ...opts,
+              sharedBindings:
+                parsedSharedBindings.size > 0
+                  ? parsedSharedBindings
+                  : undefined,
             })
+            expect(parsedResult?.code).toBe(compileResult?.code)
+            expect(parsedResult?.map).toEqual(compileResult?.map)
+            expect(parsedResult === null).toBe(compileResult === null)
 
-            await expect(compileResult?.code || code).toMatchFileSnapshot(
+            await expect(parsedResult?.code || code).toMatchFileSnapshot(
               path.join(dirs.snapshots, groupName, filename),
             )
           },
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/react/1-default/shared-identifier-options.tsx b/packages/router-plugin/tests/code-splitter/snapshots/react/1-default/shared-identifier-options.tsx
new file mode 100644
index 00000000000..bb7584f70a0
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/react/1-default/shared-identifier-options.tsx
@@ -0,0 +1,10 @@
+import { read } from "shared-identifier-options.tsx?tsr-shared=1";
+const $$splitComponentImporter = () => import('shared-identifier-options.tsx?tsr-split=component');
+import { lazyRouteComponent } from '@tanstack/react-router';
+import { createFileRoute } from '@tanstack/react-router';
+const options = {
+  codeSplitGroupings: [['component'], ['loader']],
+  loader: () => read(),
+  component: lazyRouteComponent($$splitComponentImporter, 'component')
+};
+export const Route = createFileRoute('/shared-identifier-options')(options);
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/react/1-default/shared-identifier-options@component.tsx b/packages/router-plugin/tests/code-splitter/snapshots/react/1-default/shared-identifier-options@component.tsx
new file mode 100644
index 00000000000..7a6731415d8
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/react/1-default/shared-identifier-options@component.tsx
@@ -0,0 +1,3 @@
+import { render } from "shared-identifier-options.tsx?tsr-shared=1";
+const SplitComponent = () => render();
+export { SplitComponent as component };
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/react/1-default/shared-identifier-options@errorComponent.tsx b/packages/router-plugin/tests/code-splitter/snapshots/react/1-default/shared-identifier-options@errorComponent.tsx
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/react/1-default/shared-identifier-options@notFoundComponent.tsx b/packages/router-plugin/tests/code-splitter/snapshots/react/1-default/shared-identifier-options@notFoundComponent.tsx
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/react/1-default/shared-identifier-options@shared.tsx b/packages/router-plugin/tests/code-splitter/snapshots/react/1-default/shared-identifier-options@shared.tsx
new file mode 100644
index 00000000000..9b31c488884
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/react/1-default/shared-identifier-options@shared.tsx
@@ -0,0 +1,11 @@
+const seed = {
+  value: 'shared'
+};
+const {
+  read,
+  render
+} = {
+  read: () => seed.value,
+  render: () => <div>{seed.value}</div>
+};
+export { read, render, seed };
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/react/2-components-combined-loader-separate/shared-identifier-options.tsx b/packages/router-plugin/tests/code-splitter/snapshots/react/2-components-combined-loader-separate/shared-identifier-options.tsx
new file mode 100644
index 00000000000..676bc78a5e9
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/react/2-components-combined-loader-separate/shared-identifier-options.tsx
@@ -0,0 +1,11 @@
+const $$splitComponentImporter = () => import('shared-identifier-options.tsx?tsr-split=component---errorComponent---notFoundComponent---pendingComponent');
+import { lazyRouteComponent } from '@tanstack/react-router';
+const $$splitLoaderImporter = () => import('shared-identifier-options.tsx?tsr-split=loader');
+import { lazyFn } from '@tanstack/react-router';
+import { createFileRoute } from '@tanstack/react-router';
+const options = {
+  codeSplitGroupings: [['component'], ['loader']],
+  loader: lazyFn($$splitLoaderImporter, 'loader'),
+  component: lazyRouteComponent($$splitComponentImporter, 'component')
+};
+export const Route = createFileRoute('/shared-identifier-options')(options);
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/react/2-components-combined-loader-separate/shared-identifier-options@component---errorComponent---notFoundComponent---pendingComponent.tsx b/packages/router-plugin/tests/code-splitter/snapshots/react/2-components-combined-loader-separate/shared-identifier-options@component---errorComponent---notFoundComponent---pendingComponent.tsx
new file mode 100644
index 00000000000..7a6731415d8
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/react/2-components-combined-loader-separate/shared-identifier-options@component---errorComponent---notFoundComponent---pendingComponent.tsx
@@ -0,0 +1,3 @@
+import { render } from "shared-identifier-options.tsx?tsr-shared=1";
+const SplitComponent = () => render();
+export { SplitComponent as component };
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/react/2-components-combined-loader-separate/shared-identifier-options@loader.tsx b/packages/router-plugin/tests/code-splitter/snapshots/react/2-components-combined-loader-separate/shared-identifier-options@loader.tsx
new file mode 100644
index 00000000000..f4aa78a5e67
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/react/2-components-combined-loader-separate/shared-identifier-options@loader.tsx
@@ -0,0 +1,3 @@
+import { read } from "shared-identifier-options.tsx?tsr-shared=1";
+const SplitLoader = () => read();
+export { SplitLoader as loader };
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/react/2-components-combined-loader-separate/shared-identifier-options@shared.tsx b/packages/router-plugin/tests/code-splitter/snapshots/react/2-components-combined-loader-separate/shared-identifier-options@shared.tsx
new file mode 100644
index 00000000000..9b31c488884
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/react/2-components-combined-loader-separate/shared-identifier-options@shared.tsx
@@ -0,0 +1,11 @@
+const seed = {
+  value: 'shared'
+};
+const {
+  read,
+  render
+} = {
+  read: () => seed.value,
+  render: () => <div>{seed.value}</div>
+};
+export { read, render, seed };
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/react/3-all-combined-errorComponent-separate/shared-identifier-options.tsx b/packages/router-plugin/tests/code-splitter/snapshots/react/3-all-combined-errorComponent-separate/shared-identifier-options.tsx
new file mode 100644
index 00000000000..140e67648cf
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/react/3-all-combined-errorComponent-separate/shared-identifier-options.tsx
@@ -0,0 +1,11 @@
+const $$splitComponentImporter = () => import('shared-identifier-options.tsx?tsr-split=component---loader---notFoundComponent---pendingComponent');
+import { lazyRouteComponent } from '@tanstack/react-router';
+const $$splitLoaderImporter = () => import('shared-identifier-options.tsx?tsr-split=component---loader---notFoundComponent---pendingComponent');
+import { lazyFn } from '@tanstack/react-router';
+import { createFileRoute } from '@tanstack/react-router';
+const options = {
+  codeSplitGroupings: [['component'], ['loader']],
+  loader: lazyFn($$splitLoaderImporter, 'loader'),
+  component: lazyRouteComponent($$splitComponentImporter, 'component')
+};
+export const Route = createFileRoute('/shared-identifier-options')(options);
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/react/3-all-combined-errorComponent-separate/shared-identifier-options@component---loader---notFoundComponent---pendingComponent.tsx b/packages/router-plugin/tests/code-splitter/snapshots/react/3-all-combined-errorComponent-separate/shared-identifier-options@component---loader---notFoundComponent---pendingComponent.tsx
new file mode 100644
index 00000000000..661d7851cc9
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/react/3-all-combined-errorComponent-separate/shared-identifier-options@component---loader---notFoundComponent---pendingComponent.tsx
@@ -0,0 +1,14 @@
+const seed = {
+  value: 'shared'
+};
+const {
+  read,
+  render
+} = {
+  read: () => seed.value,
+  render: () => <div>{seed.value}</div>
+};
+const SplitLoader = () => read();
+export { SplitLoader as loader };
+const SplitComponent = () => render();
+export { SplitComponent as component };
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/react/3-all-combined-errorComponent-separate/shared-identifier-options@errorComponent.tsx b/packages/router-plugin/tests/code-splitter/snapshots/react/3-all-combined-errorComponent-separate/shared-identifier-options@errorComponent.tsx
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/react/3-all-combined-errorComponent-separate/shared-identifier-options@shared.tsx b/packages/router-plugin/tests/code-splitter/snapshots/react/3-all-combined-errorComponent-separate/shared-identifier-options@shared.tsx
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/solid/1-default/shared-identifier-options.tsx b/packages/router-plugin/tests/code-splitter/snapshots/solid/1-default/shared-identifier-options.tsx
new file mode 100644
index 00000000000..dcd5a920249
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/solid/1-default/shared-identifier-options.tsx
@@ -0,0 +1,10 @@
+import { read } from "shared-identifier-options.tsx?tsr-shared=1";
+const $$splitComponentImporter = () => import('shared-identifier-options.tsx?tsr-split=component');
+import { lazyRouteComponent } from '@tanstack/solid-router';
+import { createFileRoute } from '@tanstack/solid-router';
+const options = {
+  codeSplitGroupings: [['component'], ['loader']],
+  loader: () => read(),
+  component: lazyRouteComponent($$splitComponentImporter, 'component')
+};
+export const Route = createFileRoute('/shared-identifier-options')(options);
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/solid/1-default/shared-identifier-options@component.tsx b/packages/router-plugin/tests/code-splitter/snapshots/solid/1-default/shared-identifier-options@component.tsx
new file mode 100644
index 00000000000..7a6731415d8
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/solid/1-default/shared-identifier-options@component.tsx
@@ -0,0 +1,3 @@
+import { render } from "shared-identifier-options.tsx?tsr-shared=1";
+const SplitComponent = () => render();
+export { SplitComponent as component };
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/solid/1-default/shared-identifier-options@errorComponent.tsx b/packages/router-plugin/tests/code-splitter/snapshots/solid/1-default/shared-identifier-options@errorComponent.tsx
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/solid/1-default/shared-identifier-options@notFoundComponent.tsx b/packages/router-plugin/tests/code-splitter/snapshots/solid/1-default/shared-identifier-options@notFoundComponent.tsx
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/solid/1-default/shared-identifier-options@shared.tsx b/packages/router-plugin/tests/code-splitter/snapshots/solid/1-default/shared-identifier-options@shared.tsx
new file mode 100644
index 00000000000..9b31c488884
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/solid/1-default/shared-identifier-options@shared.tsx
@@ -0,0 +1,11 @@
+const seed = {
+  value: 'shared'
+};
+const {
+  read,
+  render
+} = {
+  read: () => seed.value,
+  render: () => <div>{seed.value}</div>
+};
+export { read, render, seed };
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/solid/2-components-combined-loader-separate/shared-identifier-options.tsx b/packages/router-plugin/tests/code-splitter/snapshots/solid/2-components-combined-loader-separate/shared-identifier-options.tsx
new file mode 100644
index 00000000000..628a350db68
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/solid/2-components-combined-loader-separate/shared-identifier-options.tsx
@@ -0,0 +1,11 @@
+const $$splitComponentImporter = () => import('shared-identifier-options.tsx?tsr-split=component---errorComponent---notFoundComponent---pendingComponent');
+import { lazyRouteComponent } from '@tanstack/solid-router';
+const $$splitLoaderImporter = () => import('shared-identifier-options.tsx?tsr-split=loader');
+import { lazyFn } from '@tanstack/solid-router';
+import { createFileRoute } from '@tanstack/solid-router';
+const options = {
+  codeSplitGroupings: [['component'], ['loader']],
+  loader: lazyFn($$splitLoaderImporter, 'loader'),
+  component: lazyRouteComponent($$splitComponentImporter, 'component')
+};
+export const Route = createFileRoute('/shared-identifier-options')(options);
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/solid/2-components-combined-loader-separate/shared-identifier-options@component---errorComponent---notFoundComponent---pendingComponent.tsx b/packages/router-plugin/tests/code-splitter/snapshots/solid/2-components-combined-loader-separate/shared-identifier-options@component---errorComponent---notFoundComponent---pendingComponent.tsx
new file mode 100644
index 00000000000..7a6731415d8
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/solid/2-components-combined-loader-separate/shared-identifier-options@component---errorComponent---notFoundComponent---pendingComponent.tsx
@@ -0,0 +1,3 @@
+import { render } from "shared-identifier-options.tsx?tsr-shared=1";
+const SplitComponent = () => render();
+export { SplitComponent as component };
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/solid/2-components-combined-loader-separate/shared-identifier-options@loader.tsx b/packages/router-plugin/tests/code-splitter/snapshots/solid/2-components-combined-loader-separate/shared-identifier-options@loader.tsx
new file mode 100644
index 00000000000..f4aa78a5e67
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/solid/2-components-combined-loader-separate/shared-identifier-options@loader.tsx
@@ -0,0 +1,3 @@
+import { read } from "shared-identifier-options.tsx?tsr-shared=1";
+const SplitLoader = () => read();
+export { SplitLoader as loader };
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/solid/2-components-combined-loader-separate/shared-identifier-options@shared.tsx b/packages/router-plugin/tests/code-splitter/snapshots/solid/2-components-combined-loader-separate/shared-identifier-options@shared.tsx
new file mode 100644
index 00000000000..9b31c488884
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/solid/2-components-combined-loader-separate/shared-identifier-options@shared.tsx
@@ -0,0 +1,11 @@
+const seed = {
+  value: 'shared'
+};
+const {
+  read,
+  render
+} = {
+  read: () => seed.value,
+  render: () => <div>{seed.value}</div>
+};
+export { read, render, seed };
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/solid/3-all-combined-errorComponent-separate/shared-identifier-options.tsx b/packages/router-plugin/tests/code-splitter/snapshots/solid/3-all-combined-errorComponent-separate/shared-identifier-options.tsx
new file mode 100644
index 00000000000..9e1b4852fae
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/solid/3-all-combined-errorComponent-separate/shared-identifier-options.tsx
@@ -0,0 +1,11 @@
+const $$splitComponentImporter = () => import('shared-identifier-options.tsx?tsr-split=component---loader---notFoundComponent---pendingComponent');
+import { lazyRouteComponent } from '@tanstack/solid-router';
+const $$splitLoaderImporter = () => import('shared-identifier-options.tsx?tsr-split=component---loader---notFoundComponent---pendingComponent');
+import { lazyFn } from '@tanstack/solid-router';
+import { createFileRoute } from '@tanstack/solid-router';
+const options = {
+  codeSplitGroupings: [['component'], ['loader']],
+  loader: lazyFn($$splitLoaderImporter, 'loader'),
+  component: lazyRouteComponent($$splitComponentImporter, 'component')
+};
+export const Route = createFileRoute('/shared-identifier-options')(options);
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/solid/3-all-combined-errorComponent-separate/shared-identifier-options@component---loader---notFoundComponent---pendingComponent.tsx b/packages/router-plugin/tests/code-splitter/snapshots/solid/3-all-combined-errorComponent-separate/shared-identifier-options@component---loader---notFoundComponent---pendingComponent.tsx
new file mode 100644
index 00000000000..661d7851cc9
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/snapshots/solid/3-all-combined-errorComponent-separate/shared-identifier-options@component---loader---notFoundComponent---pendingComponent.tsx
@@ -0,0 +1,14 @@
+const seed = {
+  value: 'shared'
+};
+const {
+  read,
+  render
+} = {
+  read: () => seed.value,
+  render: () => <div>{seed.value}</div>
+};
+const SplitLoader = () => read();
+export { SplitLoader as loader };
+const SplitComponent = () => render();
+export { SplitComponent as component };
\ No newline at end of file
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/solid/3-all-combined-errorComponent-separate/shared-identifier-options@errorComponent.tsx b/packages/router-plugin/tests/code-splitter/snapshots/solid/3-all-combined-errorComponent-separate/shared-identifier-options@errorComponent.tsx
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/packages/router-plugin/tests/code-splitter/snapshots/solid/3-all-combined-errorComponent-separate/shared-identifier-options@shared.tsx b/packages/router-plugin/tests/code-splitter/snapshots/solid/3-all-combined-errorComponent-separate/shared-identifier-options@shared.tsx
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/packages/router-plugin/tests/code-splitter/test-files/react/shared-identifier-options.tsx b/packages/router-plugin/tests/code-splitter/test-files/react/shared-identifier-options.tsx
new file mode 100644
index 00000000000..a08ff706e71
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/test-files/react/shared-identifier-options.tsx
@@ -0,0 +1,15 @@
+import { createFileRoute } from '@tanstack/react-router'
+
+const seed = { value: 'shared' }
+const { read, render } = {
+  read: () => seed.value,
+  render: () => <div>{seed.value}</div>,
+}
+
+const options = {
+  codeSplitGroupings: [['component'], ['loader']],
+  loader: () => read(),
+  component: () => render(),
+}
+
+export const Route = createFileRoute('/shared-identifier-options')(options)
diff --git a/packages/router-plugin/tests/code-splitter/test-files/solid/shared-identifier-options.tsx b/packages/router-plugin/tests/code-splitter/test-files/solid/shared-identifier-options.tsx
new file mode 100644
index 00000000000..6602ecd0117
--- /dev/null
+++ b/packages/router-plugin/tests/code-splitter/test-files/solid/shared-identifier-options.tsx
@@ -0,0 +1,15 @@
+import { createFileRoute } from '@tanstack/solid-router'
+
+const seed = { value: 'shared' }
+const { read, render } = {
+  read: () => seed.value,
+  render: () => <div>{seed.value}</div>,
+}
+
+const options = {
+  codeSplitGroupings: [['component'], ['loader']],
+  loader: () => read(),
+  component: () => render(),
+}
+
+export const Route = createFileRoute('/shared-identifier-options')(options)
diff --git a/packages/router-plugin/tests/reference-pipeline.bench.ts b/packages/router-plugin/tests/reference-pipeline.bench.ts
new file mode 100644
index 00000000000..7f2f2ffef65
--- /dev/null
+++ b/packages/router-plugin/tests/reference-pipeline.bench.ts
@@ -0,0 +1,137 @@
+import { bench, describe, expect } from 'vitest'
+import { parseAst } from '@tanstack/router-utils'
+import {
+  compileCodeSplitReferenceRoute,
+  compileCodeSplitReferenceRouteFromAst,
+  computeSharedBindings,
+  computeSharedBindingsFromAst,
+  detectCodeSplitGroupingsFromAst,
+  detectCodeSplitGroupingsFromRoute,
+} from '../src/core/code-splitter/compilers'
+import { defaultCodeSplitGroupings } from '../src/core/constants'
+
+// Compare the old three-parse pipeline with the plugin's one-parse pipeline.
+// Both use identical sources/options and run all analyses before compilation.
+// Each iteration owns fresh ASTs; no cached parse or mutated tree is reused.
+function runPipeline(code: string, parseOnce: boolean) {
+  const filename = '/src/routes/benchmark.tsx'
+  const ast = parseOnce ? parseAst({ code, filename }) : undefined
+  const { groupings } = ast
+    ? detectCodeSplitGroupingsFromAst(ast)
+    : detectCodeSplitGroupingsFromRoute({ code, filename })
+  const codeSplitGroupings = groupings ?? defaultCodeSplitGroupings
+  const sharedBindings = ast
+    ? computeSharedBindingsFromAst(ast, codeSplitGroupings)
+    : computeSharedBindings({ code, filename, codeSplitGroupings })
+  const opts = {
+    code,
+    filename,
+    id: filename,
+    codeSplitGroupings,
+    sharedBindings: sharedBindings.size > 0 ? sharedBindings : undefined,
+    targetFramework: 'react' as const,
+    addHmr: false,
+  }
+  const result = ast
+    ? compileCodeSplitReferenceRouteFromAst(ast, opts)
+    : compileCodeSplitReferenceRoute(opts)
+  return { groupings, sharedBindings, code: result?.code, map: result?.map }
+}
+
+function routeSource(large: boolean, customGroups: boolean, shared: boolean) {
+  const helpers = large
+    ? Array.from(
+        { length: 120 },
+        (_, index) => `
+function renderField${index}(value: string) {
+  const label = value.trim() || 'Field ${index}'
+  return <label data-field="${index}"><span>{label}</span><input name="field${index}" defaultValue={value} /></label>
+}`,
+      ).join('\n')
+    : ''
+  const fields = large
+    ? Array.from(
+        { length: 120 },
+        (_, index) => `{renderField${index}('Value ${index}')}`,
+      ).join('\n')
+    : '<span>Small route</span>'
+  return `
+import { createFileRoute } from '@tanstack/react-router'
+${shared ? "const state = { title: 'Shared title' }" : ''}
+${helpers}
+function Component() {
+  return <section><h1>${shared ? '{state.title}' : 'Independent title'}</h1>${fields}</section>
+}
+const options = {
+  ${customGroups ? "codeSplitGroupings: [['component', 'pendingComponent'], ['loader']]," : ''}
+  loader: () => ${shared ? 'state.title' : "'Independent data'"},
+  component: Component,
+  pendingComponent: () => <p>Loading</p>,
+}
+export const Route = createFileRoute('/benchmark')(options)
+`
+}
+
+// Run each workload in fresh processes with both AB and BA to check ordering
+// sensitivity without changing its inputs or timing settings between runs.
+const order = process.env.REFERENCE_BENCH_ORDER ?? 'AB'
+if (order !== 'AB' && order !== 'BA') {
+  throw new Error('REFERENCE_BENCH_ORDER must be AB or BA')
+}
+
+function benchmarkPipeline(name: string, code: string, shared = false) {
+  describe(name, () => {
+    const baseline = runPipeline(code, false)
+    const candidate = runPipeline(code, true)
+    expect(candidate).toEqual(baseline)
+    expect(candidate.sharedBindings.size > 0).toBe(shared)
+    expect(candidate.code).toContain('$$splitComponentImporter')
+    expect(candidate.map?.sourcesContent).toEqual([code])
+
+    for (const parseOnce of order === 'AB' ? [false, true] : [true, false]) {
+      bench(
+        parseOnce ? 'candidate: one parse' : 'baseline: three parses',
+        () => {
+          runPipeline(code, parseOnce)
+        },
+        { time: 5000, iterations: 200, warmupTime: 1000 },
+      )
+    }
+  })
+}
+
+for (const [name, body] of [
+  [
+    'imported-component-only',
+    `
+import Component from './Component'
+export const Route = createFileRoute('/benchmark')({ component: Component })`,
+  ],
+  [
+    'inline-component-only',
+    `
+export const Route = createFileRoute('/benchmark')({ component: () => <div>Page</div> })`,
+  ],
+  [
+    'single-group-local',
+    `
+const title = 'Page'
+function Component() { return <div>{title}</div> }
+export const Route = createFileRoute('/benchmark')({ component: Component })`,
+  ],
+] as const) {
+  benchmarkPipeline(
+    `tiny/default/${name}`,
+    `import { createFileRoute } from '@tanstack/react-router'\n${body}`,
+  )
+}
+
+for (const large of [false, true]) {
+  for (const customGroups of [false, true]) {
+    for (const shared of [false, true]) {
+      const name = `${large ? 'large-synthetic-declaration-heavy' : 'small'}/${customGroups ? 'custom' : 'default'}/${shared ? 'shared' : 'no-shared'}`
+      const code = routeSource(large, customGroups, shared)
+      benchmarkPipeline(name, code, shared)
+    }
+  }
+}
diff --git a/packages/router-plugin/tests/reference-pipeline.test.ts b/packages/router-plugin/tests/reference-pipeline.test.ts
new file mode 100644
index 00000000000..24d8948293b
--- /dev/null
+++ b/packages/router-plugin/tests/reference-pipeline.test.ts
@@ -0,0 +1,419 @@
+import { readFile } from 'node:fs/promises'
+import path from 'node:path'
+import * as t from '@babel/types'
+import { describe, expect, it, vi } from 'vitest'
+import { parseAst } from '@tanstack/router-utils'
+import {
+  compileCodeSplitReferenceRoute,
+  compileCodeSplitSharedRoute,
+  compileCodeSplitVirtualRoute,
+  computeSharedBindings,
+  detectCodeSplitGroupingsFromRoute,
+} from '../src/core/code-splitter/compilers'
+import { getFrameworkHmrCompilerPlugins } from '../src/core/code-splitter/plugins/framework-plugins'
+import { defaultCodeSplitGroupings } from '../src/core/constants'
+import { createRouterCodeSplitterPlugin } from '../src/core/router-code-splitter-plugin'
+import { createRouterPluginContext } from '../src/core/router-plugin-context'
+import { normalizePath } from '../src/core/utils'
+import type { Config } from '../src/core/config'
+import type { CodeSplitCompilerPlugin } from '../src/core/code-splitter/plugins'
+import type { CodeSplitGroupings } from '../src/core/constants'
+
+vi.mock('@tanstack/router-utils', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('@tanstack/router-utils')>()
+  return { ...actual, parseAst: vi.fn(actual.parseAst) }
+})
+
+async function createHarness(
+  options: Partial<Config> = {},
+  command: 'serve' | 'build' = 'serve',
+) {
+  const filename = normalizePath(path.resolve('src/routes/pipeline.tsx'))
+  const context = createRouterPluginContext()
+  context.routesByFile.set(filename, { routeId: '/pipeline' })
+  const result = createRouterCodeSplitterPlugin(options, context)
+  const plugins = Array.isArray(result) ? result : [result]
+  const reference = plugins[0]!
+  const hook = reference.vite!.configResolved!
+  const config = {
+    root: process.cwd(),
+    command,
+    plugins: [{ name: reference.name }],
+  } as never
+  if (typeof hook === 'function') {
+    await hook.call({} as never, config)
+  } else {
+    await hook.handler.call({} as never, config)
+  }
+
+  return {
+    filename,
+    transform(code: string, query = '') {
+      const plugin = query.startsWith('?tsr-shared')
+        ? plugins[2]!
+        : query
+          ? plugins[1]!
+          : reference
+      const transform = plugin.transform!
+      if (typeof transform === 'function') {
+        throw new Error('Expected object transform')
+      }
+      return transform.handler.call({} as never, code, `${filename}${query}`)
+    },
+  }
+}
+
+describe('reference pipeline', () => {
+  it('parses the reference source once per transform', async () => {
+    const harness = await createHarness({}, 'build')
+    const code = `
+import { createFileRoute } from '@tanstack/react-router'
+export const Route = createFileRoute('/pipeline')({ component: () => <div /> })`
+    vi.mocked(parseAst).mockClear()
+    await harness.transform(code)
+    expect(parseAst).toHaveBeenCalledTimes(1)
+  })
+
+  it.each(['react', 'solid', 'vue'] as const)(
+    'preserves %s compiler hooks, HMR and sourcemaps after analysis',
+    async (targetFramework) => {
+      const fixture = await readFile(
+        new URL(
+          './code-splitter/test-files/react/shared-identifier-options.tsx',
+          import.meta.url,
+        ),
+        'utf8',
+      )
+      const code = fixture.replace(
+        '@tanstack/react-router',
+        `@tanstack/${targetFramework}-router`,
+      )
+      for (const hmrStyle of ['vite', 'webpack'] as const) {
+        const observed: Array<Array<string>> = []
+        const mutationPlugin: CodeSplitCompilerPlugin = {
+          name: 'remove-loader-after-analysis',
+          onRouteOptions({ routeOptions, opts }) {
+            observed.push([...opts.sharedBindings!].sort())
+            // Removing one consumer must not retroactively change sharing.
+            routeOptions.properties = routeOptions.properties.filter(
+              (prop) =>
+                !(
+                  t.isObjectProperty(prop) &&
+                  t.isIdentifier(prop.key, { name: 'loader' })
+                ),
+            )
+            return { modified: true }
+          },
+        }
+        const harness = await createHarness({
+          target: targetFramework,
+          plugin: { hmr: { style: hmrStyle } },
+          codeSplittingOptions: { compilerPlugins: [mutationPlugin] },
+        })
+        const { filename } = harness
+        const { groupings } = detectCodeSplitGroupingsFromRoute({
+          code,
+          filename,
+        })
+        const sharedBindings = computeSharedBindings({
+          code,
+          filename,
+          codeSplitGroupings: groupings!,
+        })
+        const baseline = compileCodeSplitReferenceRoute({
+          code,
+          filename,
+          id: filename,
+          codeSplitGroupings: groupings!,
+          targetFramework,
+          sharedBindings,
+          addHmr: true,
+          hmrStyle,
+          hmrRouteId: '/pipeline',
+          compilerPlugins: [
+            ...(getFrameworkHmrCompilerPlugins({
+              targetFramework,
+              hmrStyle,
+            }) ?? []),
+            mutationPlugin,
+          ],
+        })
+        const candidate = await harness.transform(code)
+        expect(candidate).toMatchObject({
+          code: baseline!.code,
+          map: baseline!.map,
+        })
+        expect(baseline!.map?.sourcesContent).toEqual([code])
+        expect(observed).toEqual([
+          ['read', 'render', 'seed'],
+          ['read', 'render', 'seed'],
+        ])
+      }
+    },
+  )
+
+  it.each(['serve', 'build'] as const)(
+    'refreshes reference, virtual and shared output across source changes in %s',
+    async (command) => {
+      const harness = await createHarness(
+        { codeSplittingOptions: { addHmr: false } },
+        command,
+      )
+      for (const name of ['a', 'b', undefined, 'a']) {
+        const code = `
+import { createFileRoute } from '@tanstack/react-router'
+${name ? `const ${name} = { value: '${name}' }` : ''}
+export const Route = createFileRoute('/pipeline')({
+  loader: () => ${name ? `${name}.value` : "'none'"},
+  component: () => <div>{${name ? `${name}.value` : "'none'"}}</div>,
+})`
+        const { filename } = harness
+        const sharedBindings = computeSharedBindings({
+          code,
+          filename,
+          codeSplitGroupings: defaultCodeSplitGroupings,
+        })
+        expect([...sharedBindings]).toEqual(name ? [name] : [])
+        const reference = compileCodeSplitReferenceRoute({
+          code,
+          filename,
+          id: filename,
+          targetFramework: 'react',
+          codeSplitGroupings: defaultCodeSplitGroupings,
+          sharedBindings,
+          addHmr: false,
+        })!
+        const virtual = compileCodeSplitVirtualRoute({
+          code,
+          filename: `${filename}?tsr-split=component`,
+          splitTargets: ['component'],
+          sharedBindings,
+        })
+        for (const [query, expected] of [
+          ['', reference],
+          ['?tsr-split=component', virtual],
+        ] as const) {
+          expect(await harness.transform(code, query)).toMatchObject({
+            code: expected.code,
+            map: expected.map,
+          })
+          expect(expected.map?.sourcesContent).toEqual([code])
+        }
+        const shared = await harness.transform(code, '?tsr-shared=1')
+        if (name) {
+          const expected = compileCodeSplitSharedRoute({
+            code,
+            filename: `${filename}?tsr-shared=1`,
+            sharedBindings,
+          })
+          expect(shared).toMatchObject({
+            code: expected.code,
+            map: expected.map,
+          })
+          expect(expected.map?.sourcesContent).toEqual([code])
+          expect(expected.code).toContain(`export { ${name} }`)
+        } else {
+          expect(shared).toBeNull()
+        }
+      }
+    },
+  )
+
+  it('preserves scope-aware mutations and binding inspection across compiler hooks', async () => {
+    const observations: Array<Array<string>> = []
+    const compilerPlugins: Array<CodeSplitCompilerPlugin> = [
+      {
+        name: 'rename-and-insert',
+        onRouteOptions({ programPath, insertionPath }) {
+          programPath.scope.rename('message', 'renamedMessage')
+          insertionPath.insertBefore(
+            t.variableDeclaration('const', [
+              t.variableDeclarator(
+                t.identifier('injected'),
+                t.identifier('renamedMessage'),
+              ),
+            ]),
+          )
+          programPath.scope.crawl()
+          return { modified: true }
+        },
+      },
+      {
+        name: 'inspect-renamed-bindings',
+        onRouteOptions({ programPath, routeOptions }) {
+          expect(programPath.scope.hasBinding('message')).toBe(false)
+          const renamed = programPath.scope.getBinding('renamedMessage')!
+          const inserted = programPath.scope.getBinding('injected')!
+          observations.push([
+            renamed.identifier.name,
+            inserted.identifier.name,
+            ...renamed.referencePaths.map((reference) => {
+              t.assertIdentifier(reference.node)
+              return reference.node.name
+            }),
+          ])
+          routeOptions.properties.push(
+            t.objectProperty(
+              t.identifier('context'),
+              t.arrowFunctionExpression([], t.identifier('injected')),
+            ),
+          )
+          programPath.scope.crawl()
+          expect(programPath.scope.getBinding('injected')!.referenced).toBe(
+            true,
+          )
+          return { modified: true }
+        },
+      },
+    ]
+    const harness = await createHarness(
+      { codeSplittingOptions: { compilerPlugins } },
+      'build',
+    )
+    const code = `
+import { createFileRoute } from '@tanstack/react-router'
+const message = 'scope-visible'
+const options = { loader: () => message, component: () => <div>page</div> }
+export const Route = createFileRoute('/pipeline')(options)`
+    const baseline = compileCodeSplitReferenceRoute({
+      code,
+      filename: harness.filename,
+      id: harness.filename,
+      codeSplitGroupings: defaultCodeSplitGroupings,
+      targetFramework: 'react',
+      compilerPlugins,
+    })!
+    const candidate = await harness.transform(code)
+    expect(candidate).toMatchObject({ code: baseline.code, map: baseline.map })
+    expect(baseline.code).toContain('const injected = renamedMessage')
+    expect(baseline.code).toContain('context: () => injected')
+    expect(observations).toHaveLength(2)
+    expect(observations[1]).toEqual(observations[0])
+  })
+
+  it('preserves Start client deletion, shared extraction and server-only import DCE', async () => {
+    // The client router integration in both Vite and Rsbuild uses these keys.
+    const deleteNodes = ['ssr', 'server', 'headers']
+    const harness = await createHarness(
+      { codeSplittingOptions: { deleteNodes } },
+      'build',
+    )
+    const code = `
+import { createFileRoute } from '@tanstack/react-router'
+import { serverPolicy, handleRequest, makeHeaders } from './server-only'
+const shared = { title: 'client-visible' }
+export const Route = createFileRoute('/pipeline')({
+  ssr: () => serverPolicy(),
+  server: { handlers: { GET: () => handleRequest() } },
+  headers: () => makeHeaders(),
+  loader: () => shared.title,
+  component: () => <div>{shared.title}</div>,
+})`
+    const sharedBindings = computeSharedBindings({
+      code,
+      filename: harness.filename,
+      codeSplitGroupings: defaultCodeSplitGroupings,
+    })
+    expect([...sharedBindings]).toEqual(['shared'])
+    const baseline = compileCodeSplitReferenceRoute({
+      code,
+      filename: harness.filename,
+      id: harness.filename,
+      codeSplitGroupings: defaultCodeSplitGroupings,
+      targetFramework: 'react',
+      deleteNodes: new Set(deleteNodes),
+      sharedBindings,
+    })!
+    expect(await harness.transform(code)).toMatchObject({
+      code: baseline.code,
+      map: baseline.map,
+    })
+    expect(baseline.code).not.toMatch(
+      /server-only|serverPolicy|handleRequest|makeHeaders|ssr:|server:|headers:/,
+    )
+    expect(baseline.code).toContain('tsr-shared=1')
+    expect(baseline.code).toContain('$$splitComponentImporter')
+    expect(baseline.map?.sourcesContent).toEqual([code])
+  })
+
+  it.each([
+    {
+      sourceGroups: undefined,
+      callbackGroups: undefined,
+      expected: [['loader']],
+    },
+    {
+      sourceGroups: undefined,
+      callbackGroups: [['component']],
+      expected: [['component']],
+    },
+    {
+      sourceGroups: [['loader', 'component']],
+      callbackGroups: [['component']],
+      expected: [['loader', 'component']],
+    },
+    { sourceGroups: [], callbackGroups: [['component']], expected: [] },
+  ] as Array<{
+    sourceGroups?: CodeSplitGroupings
+    callbackGroups?: CodeSplitGroupings
+    expected: CodeSplitGroupings
+  }>)(
+    'preserves grouping precedence: $sourceGroups / $callbackGroups',
+    async ({ sourceGroups, callbackGroups, expected }) => {
+      const splitBehavior = vi.fn(() => callbackGroups)
+      const harness = await createHarness({
+        codeSplittingOptions: {
+          addHmr: false,
+          defaultBehavior: [['loader']],
+          splitBehavior,
+        },
+      })
+      const code = `
+import { createFileRoute } from '@tanstack/react-router'
+export const Route = createFileRoute('/pipeline')({
+  ${sourceGroups ? `codeSplitGroupings: ${JSON.stringify(sourceGroups)},` : ''}
+  loader: () => 'data', component: () => <div>page</div>,
+})`
+      const baseline = compileCodeSplitReferenceRoute({
+        code,
+        filename: harness.filename,
+        id: harness.filename,
+        codeSplitGroupings: expected,
+        targetFramework: 'react',
+        addHmr: false,
+      })
+      const candidate = await harness.transform(code)
+      if (baseline === null) {
+        expect(candidate).toBeNull()
+      } else {
+        expect(candidate).toMatchObject({
+          code: baseline.code,
+          map: baseline.map,
+        })
+      }
+      expect(splitBehavior).toHaveBeenCalledExactlyOnceWith({
+        routeId: '/pipeline',
+      })
+    },
+  )
+
+  it('validates callback groups even when the source specifies groups', async () => {
+    const onRouteOptions = vi.fn()
+    const harness = await createHarness({
+      codeSplittingOptions: {
+        splitBehavior: () => [['invalid']] as unknown as CodeSplitGroupings,
+        compilerPlugins: [{ name: 'observe', onRouteOptions }],
+      },
+    })
+    const code = `
+import { createFileRoute } from '@tanstack/react-router'
+export const Route = createFileRoute('/pipeline')({
+  codeSplitGroupings: ${JSON.stringify(defaultCodeSplitGroupings)},
+  component: () => <div>page</div>,
+})`
+    expect(() => harness.transform(code)).toThrow(
+      'The groupings returned when using `splitBehavior`',
+    )
+    expect(onRouteOptions).not.toHaveBeenCalled()
+  })
+})