Tools/Next.js Build Error Decoder
Free tool — runs entirely in your browser

Next.js Build Error Decoder

Paste the raw output of a failing next build or a stuck next dev. The decoder matches 13+ real failure signatures and tells you which one hit you, why, and the exact fix. Nothing you paste leaves your browser.

Runs entirely in your browser — nothing is uploaded.

Errors this decoder recognizes

Each signature comes from an error we have hit and documented — the diagnosis links to the deep-dive with reproduction steps and every variant of the fix.

useSearchParams() should be wrapped in a suspense boundaryread the fix →
ChunkLoadError: Loading chunk failedread the fix →
Dynamic server usage: couldn't be rendered staticallyread the fix →
window is not definedread the fix →
Module not found: Can't resolve …read the fix →
JavaScript heap out of memoryread the fix →
Hydration failed / text content does not matchread the fix →
Dev server stuck on "compiling…"read the fix →
EADDRINUSE: port 3000 already in useread the fix →
process.env.X is undefinedread the fix →
Cannot find module 'next/babel'read the fix →
next/image hostname not configuredread the fix →
next lint removed (Next.js 16)read the fix →

Build passes but production is broken?

A green build is not a working app. Check your env variables with the Env Leak Checker and read the postmortem of a build that passed while production silently broke.

Read the postmortem