Warn when overriding Cache-Control header on /_next/ routes
#88353
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
nextjs-bot
added
created-by: Turbopack team
Collaborator
Stats from current PR✅ No significant changes detected📊 All Metrics📖 Metrics GlossaryDev Server Metrics:
Build Metrics:
Change Thresholds:
⚡ Dev Server
📦 Dev Server (Webpack) (Legacy)📦 Dev Server (Webpack)
⚡ Production Builds
📦 Production Builds (Webpack) (Legacy)📦 Production Builds (Webpack)
📦 Bundle SizesBundle Sizes⚡ TurbopackClient Main Bundles: **431 kB** → **431 kB** ✅ -16 B82 files with content-based hashes (individual files not comparable between builds) Server Middleware
Build DetailsBuild Manifests
📦 WebpackClient Main Bundles
Polyfills
Pages
Server Edge SSR
Middleware
Build DetailsBuild Manifests
Build Cache
🔄 Shared (bundler-independent)Runtimes
|
andrewimm
force-pushed
the
andrewimm/cache-control-warn
branch
from
d0f4df7 to
8fabeab
Compare
Collaborator
Tests Passed |
lukesandberg
approved these changes
Jan 10, 2026
Custom `Cache-Control` headers on `/_next/` routes can cause hard-to-debug development behaviors. Normally the dev server sends no-cache values to ensure that assets are always fresh. If a developer sets the max-age or the immutable flag, the browser can cache resources between requests, even if the source changes. Adding a warning will at least make this problem easier to debug.
andrewimm
force-pushed
the
andrewimm/cache-control-warn
branch
from
8fabeab to
24ec77c
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Custom
Cache-Controlheaders on/_next/routes can cause hard-to-debug development behaviors. Normally the dev server sends no-cache values to ensure that assets are always fresh. If a developer sets the max-age or immutable flag,, the browser can cache resources between requests, even if the source changes.Adding a warning will at least make this problem easier to debug.