JAVASCRIPT GUIDE
JavaScript Memory Leaks
By the HireReadyAI team · 8 min read
Listeners, timers, unbounded caches, detached DOM nodes, and how to detect leaks.
Common causes
- Forgotten event listeners
- Uncleared timers/intervals
- Caches without bounds or TTLs
- Detached DOM nodes retained by JS references
- Closures holding large structures longer than needed
Detection
In browsers, use Performance/Memory tools and heap snapshots. In Node, watch heap used over time and take snapshots under load. Look for retained size growing across GC cycles.
Fixes
Remove listeners on teardown, clear timers, bound caches, null out large references when done, and avoid accidental globals. In React, clean up effects properly.