documents/dev/nextjs.md
Table of Contents
CatchRoutes
experimental-analyze
Added in Next.js v16.1.0. Analyzes your application's bundle output using Turbopack. Helps understand the size and composition of bundles (JavaScript, CSS, other assets). Does not produce a build artifact.
npx next experimental-analyze
By default, starts a local server (port 4000) after analysis so you can explore bundle composition in the browser:
- Filter bundles by route
- Switch between client and server views
- View the full import chain showing why a module is included
- Trace imports across server-to-client component boundaries and dynamic imports
Options
| Option | Description |
|---|---|
-h, --help |
Show all available options |
[directory] |
Directory to analyze (default: current dir) |
--no-mangling |
Disable mangling (may affect perf, debugging only) |
--profile |
Enable production profiling for React |
-o, --output |
Write analysis to .next/diagnostics/analyze without starting server |
--port <port> |
Port for the analyzer server (default: 4000, env: PORT) |
Example — save analysis to disk
npx next experimental-analyze --output
cp -r .next/diagnostics/analyze ./analyze-before-refactor