Next.js: Plugging Memory Leaks and Taming V8 Deopts
A cluster of fixes targeted long-running-server memory leaks in the sandbox and compression layers, while a separate wave of performance work used a new deopt-detection tool to fix V8 hidden-class instability in the segment cache and HMR paths.
Duration: PT2M41S
Episode overview
This episode is a short developer briefing from Next.js.
It explains recent repository work in plain language.
- Show: Next.js
- Published: 2026-07-25T13:09:47Z
- Audio duration: PT2M41S
Transcript excerpt
This excerpt keeps the crawler page concise. Listen to the episode or use the RSS feed for the full update.
Good day, and welcome to the Next.js briefing for July 25th, 2026.
Today's biggest signal: two independent memory leaks in long-running servers got fixed, and a new benchmarking tool is now driving a wave of targeted performance patches. If you run self-hosted or standalone Next.js servers, this is your update.
First, memory leaks. Pete Hunt landed two fixes: PR 96161 stops the Edge sandbox from permanently tracking one-shot timeouts after they fire, which was causing step-wise heap growth toward OOM. PR 96173 fixes a nastier case, where a client disconnecting mid-response left the compression library's zlib stream alive,…
Second theme: source maps got both faster and more correct. Dan's PR 95946 switched Turbopack's dev sourcemaps from inline data URIs to file-based ones, fixing a 12-second dev slowdown and memory bloat on large files. The follow-up, PR 96198, caches parsed source maps and consumers instead of redoing that work per…
Third: performance-by-measurement. Andrew Clark shipped a new deopt-detection benchmark, and used it to fix three separate V8 megamorphic hot paths — route tree slots, optimistic route param handling, and vary-path nodes — all in the segment cache.…
Also…
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