Chrome DevTools · Memory ·
DevTools heap snapshots now flag dead closure variables
Chrome DevTools November 2026 heap snapshots flag dead context fields: variables kept alive by shared closure contexts that nothing reads. How they leak.
A memory leak can come from a variable that no running code reads. In V8, closures created in the same function share one context object. If a long-lived closure, say an interval callback, keeps that context alive, a large array that only a finished closure used stays in memory as well.
What the November update adds
The November 2026 DevTools update (20 October) says the Memory panel now detects unused closure variables that remain retained in V8 execution contexts. Take a heap snapshot and it flags these dead context fields, ranked by how much memory they hold.
Sources
I post short notes like this on LinkedIn.
