Next.js Release Notes

Note

This release is backporting bug fixes. It does not include all pending features/changes on canary.

Core Changes

• Turbopack: Update to swc_core v50.2.3 (#87841) (#88296)
  • Fixes a crash when processing mdx files with multibyte characters. (#87713)
• Turbopack: mimalloc upgrade and enabling it on musl (#88503) (#87815) (#88426)
  • Fixes a significant performance issue on musl-based Linux distributions (e.g. Alpine in Docker) related to musl's allocator.
  • Other platforms have always used mimalloc, but we previously did not use mimalloc on musl because of compilation issues that have since been resolved.

Credits

Huge thanks to @mischnic for helping!

Tip
Check out our Next v16.1 Blog Post to learn more about this release.

Core Changes

• fix: Rspack throw error when using ForceCompleteRuntimePlugin: #85221
• fix: build CLI output not displaying Proxy (Middleware) when nodejs runtime: #85403
• fix: staleTimes.static should consistently enforce a 30s minimum: #85479
• [turbopack] fix build of empty entries of pages: #84873
• Cache the head separately from the route tree: #84724
• Allow inspecting dev server on default port with next dev --inspect: #85037
• Avoid proxying React modules through workUnitStore: #85486
• fix: redirect should always return updated router state: #85533
• Upgrade React from b4455a6e-20251027 to 4f931700-20251029 : #85518
• [turbopack] Move generation of cacheLife types out of the webpack plugin and into the dev bundler directly: #85539
• Ensure user-space stack frame for 'use cache' in page/layout component: #85519
• Update parallel routes in build-complete: #85546
• fully remove clientSegmentCache flag: #85541
• [turbopack] Support relative paths in turbopack source maps.: #85146
• Release unnecessary memory on hydration finish: #84967
• Preserve interception markers in parameter types: #85526
• move segment cache entries to top level segment-cache dir: #85542
• Upgrade React from 4f931700-20251029 to 561ee24d-20251101 : #85670
• [devtools] Remove title from preferences: #85698
• Update font data: #85708
• Don't invalidate hot reloader excessively during dev server boot: #85732
• [codemod] fix: next-lint-to-eslint-cli did not handle 'next' plugin: #85749
• Upgrade React from 561ee24d-20251101 to 67f7d47a-20251103 : #85762
• Tracing: Fix memory leak in span map: #85529
• Fix documentation typo in refresh function: #85696
• fix: eslint-config-next types was exporting to dist/src: #85768
• Upgrade React from 67f7d47a-20251103 to f646e8ff-20251104 : #85772
• remove unused RSC payload property: #85746
• [runtime prefetching]: fix runtime prefetching when deployed: #85595
• Turbopack: next build --analyze: #85197
• Build: Log amount of workers during static generation: #85706
• Upgrade React from f646e8ff-20251104 to dd048c3b-20251105 : #85819
• Sync devFallbackParams when generateStaticParams change: #85741
• chore: upgrade rspack 1.6.0: #84210
• [mcp] get_routes mcp tool: #85773
• Split each path param into a separate cache key : #85758
• [turbopack] change server source maps in production to use relative paths: #85576
• fix: skip collecting metadata for app-error in webpack: #85892
• fix: support root span attributes with a custom server: #85521
• fix isDynamicRSC condition when deployed: #85919
• [turbopack] Make it possible to synchronously access native bindings: #85787
• Upgrade React from dd048c3b-20251105 to fa50caf5-20251107 : #85906
• Fix telemetry event loss on build failures and server shutdown: #85867
• Remove one stack frame from 'use cache' call stacks: #85966
• Upgrade React from fa50caf5-20251107 to 52684925-20251110 : #85980
• Deployment adapter: fix metadata for "/" route: #85820
• Enable React's default Transition indicator behind a flag: #86000
• update routes-manifest to include whether app has pages routes: #86051
• Fix 404 responses for interception routes with missing children slots: #85779
• Build: Share StaticWorker between static check and static generation: #85860
• [devtool] highlight all link in error message: #86084
• fix(nodejs-middleware): await for body cloning to be properly finalized: #85418
• Add build-time validation to detect ambiguous app routes: #85834
• Don't use inspector frontend URLs from other processes: #86082
• Upgrade React from 52684925-20251110 to 93fc5740-20251113 : #86103
• [next-upgrade] Force install of dev dependencies: #86119
• Fix telemetry event race condition in webpack worker for @vercel/og detection: #86145
• Turbopack: Add bundle analyzer UI to next build --experimental-analyze: #85788
• Upgrade React from 93fc5740-20251113 to fb2177c1-20251114 : #86155
• fix: cacheMaxMemorySize should not disable dev HMR cache: #86164
• Fix streaming server actions: #86148
• Allow attaching a debugger when next dev is already running: #86083
• Introduce next analyze : a built-in bundle analyzer for Turbopack: #85915
• Turbopack: add experimental.turbopackClient/ServerSideNestedAsyncChunking : #85827
• next analyze: annotate polyfill modules in UI: #86062
• Stop adding additional padding to Next.js logs: #86139
• [next-upgrade] Add next upgrade : #86120
• Fix prerendering of interception routes with generateStaticParams: #85835
• [Segment Cache] Re-implement refresh reducer: #84426
• Upgrade React from fb2177c1-20251114 to 0972e239-20251118 : #86263
• next analyze: Make ipv6 server links valid and normalize localhost: #86219
• fix: prevent fetch abort errors propagating to user error boundaries: #86277
• chore(turbopack-node): remove some outdated codes: #86111
• [devtools] Ensure Chrome DevTools workspace can connect with proxy rewrites: #86289
• Fix log log alignment in spinners: #86298
• fix: Rename proxy.js to middleware.js in NFT file: #86214
• Turbopack: allow trace level tracing: #86255
• Allow SSR to finish microtasky work before flushing: #86311
• Turbopack: fix passing project options from napi: #86256
• [Cache Components] Atomic setTimeouts: #86093
• Turbopack: add experimental.turbopackInputSourceMaps and respect serverSourceMaps: #86340
• [Cache Components] Discriminate static shell validation errors by type: #85747
• Turbopack: add NEXT_TURBOPACK_WRITE_ROUTES_HASHES_MANIFEST to write hashes into manifest: #86257
• Add reasons for some server-external-packages: #86254
• Send dynamic validation errors to browser via WebSocket: #85818
• Delete un-used prefetch outputs with PPR: #86100
• Revert "Turbopack: add bundle analyzer to versioning and add dependen…: #86394
• Turbopack: add bundle-analyzer to versioning and add dependency: #86355
• fix issue - #86365 : #86366
• Turbopack: fix import chain by determining depth locally per route: #86350
• Use JSONC for default server-external-packages: #86252
• add debug logs to onSegmentPrerenderError: #86358
• Skip request if "full" prefetch is already pending: #86405
• fix: Rename proxy.js to middleware.js in NFT file (#86214)
• fix: prevent fetch abort errors propagating to user error boundaries (#86277)
• Turbopack: fix passing project options from napi (#86256)
• Eslint: Improve Google Tag manager third parties message: #51903
• [ts-plugin] keep showing the types in the function body: #86273
• [turbopack] Enable the filesystem cache for dev in canary builds: #85940
• docs: fix typos in packages: #82508
• Turbopack: Expose an environment variable for exposing the detail field of issues: #86518
• Turbopack: inner graph tree shaking: #85973
• [next-upgrade] Fall back to npx if yarn dlx is not available: #86384
• Update font data: #86521
• Convert any export from a 'use cache' module to a cache function: #86014
• fix(nodejs-middleware): await for body cloning to be properly finalized (#85418)
• Fix stale dev types causing build failure after route deletion: #86489
• bump the browserslist version to silence a warning in CI (#86625)
• add bundle analyzer as dev dependency to next: #86497
• Remove obsolete setReferenceManifestsSingleton call: #86574
• Add flag to show ignore listed frames: #86285
• Add alinea to server-external-packages.json: #55006
• Fix error logging for 'use cache' runtime errors in production: #86500
• Upgrade React from 8ac5f4eb-20251119 to fd524fe0-20251121 : #86473
• Add "@zenstackhq/runtime" to server-external-packages.json: #54829
• [Cache Components] Ensure cache misses always cause a restart in dev: #86583
• bump the browserslist version to silence a warning in CI: #86625
• Turbopack: import to char not replaced: #86573
• Revert "add bundle analyzer as dev dependency to next (#86497)": #86672
• Handle cross-page client reference contamination in development: #86591
• Match behavior of baseline-browser-mapping with caniuse-lite: #86653
• Turbopack: don't generateBuildId in dev: #86581
• [devtool] unify the bundler field: #86514
• Turbopack: normalize distDir separators: #86697
• Cover org package external in externals-transitive test: #86691
• [turbopack] Enable filesystem cache by default for development: #85975
• Log generate params duration in dev: #86726
• [CC] Fix hanging dynamic promise when abandoning render: #86690
• Convert Windows paths as well when reading sourcemap: #86723
• Deterministic functions-config-manifest.json: #86736
• Abstract deployment id access into module: #86727
• Deterministically order pages in the MappedPages structure: #86744
• [turbopack] move edge entry wrapper to build template: #86699
• Properly type ComponentMod: #86765
• Properly type edge handler fn: #86766
• Remove unused Server.responseCache: #86768
• [Cache Components] Fast setImmediate: #86018
• [devtool] make the draggable content selective: #86816
• Create server module map proxy only once: #86750
• fix(next/image): add ?dpl query string for local images (without static import): #86485
• fix(next/image): handle ?dpl for src without protocol: #86836
• Upgrade React from 7dc903cd-20251203 to 66ae640b-20251204 : #86843
• Upgrade React from 66ae640b-20251204 to 378973b3-20251205 : #86852
• Turbopack: remove pages router double template: #86842
• Introduce NextConfigRuntime: #86812
• Generate required-server-files before prerendering: #86830
• Update react version in cna templates (#86950)
• Include nextConfig in edge runtime via separate manifest: #86769
• Fix required-server-files: #86875
• Add pino-related packages to server-external-packages: #86884
• Fix validateTurboNextConfig running for next start: #86886
• Add experimental.runtimeS... Read more