Next.js Build Out of Memory - Fix in CI

A large Next build can exhaust the V8 heap, especially on small CI containers with tight memory limits. The process aborts mid-compile with an OOM. Faster, larger managed runners (Latchkey) give the build the headroom it needs and auto-retry transient OOM-killed jobs.

What this error means

The build dies with FATAL ERROR: Reached heap limit Allocation failed - JavaScript heap out of memory, often partway through compilation.

node

<--- Last few GCs --->
[1:0x...] FATAL ERROR: Reached heap limit Allocation failed -
JavaScript heap out of memory
 1: 0x... node::Abort()

Common causes

Heap limit too low for the app

The default Node heap is smaller than the build needs for a large dependency graph.

Undersized runner

A small CI container caps total memory; the OS OOM-killer reaps the build before it finishes.

How to fix it

Raise the Node heap

Increase the max old space size for the build process.

Terminal

NODE_OPTIONS=--max-old-space-size=4096 npm run build

Build on a larger runner

Run next build on a runner with more memory so the build is not OOM-killed.

CI config

# choose a higher-memory runner for the build job

How to prevent it

Right-size the build runner to the app and cap the heap accordingly.
Watch peak build memory so growth does not silently approach the limit.