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Memory spike: 3 processes peaked at 12.7 GB combined on 18 GB machine (v2.1.34, macOS native) #24113
Closed as not planned
Description
Preflight Checklist
- I have searched existing issues and this hasn't been reported yet
- This is a single bug report
- I am using the latest version of Claude Code
What's Wrong?
Three Claude Code processes spiked to a combined peak of 12.7 GB on an 18 GB machine (71% of total RAM). System swap hit 96%.
This is not a team/multi-agent session. Just normal single-user work — reading files, editing code, running tools.
The Numbers
Captured with footprint -p claude --swapped on Feb 8, 2026:
Peak memory per process:
| PID | Current | Peak | Top Consumer |
|---|---|---|---|
| 97354 | 4,414 MB | 5,810 MB | WebKit malloc: 3,057 MB |
| 94672 | 1,597 MB | 3,715 MB | WebKit malloc: 850 MB |
| 63744 | 2,276 MB | 3,215 MB | WebKit malloc: 1,738 MB |
| 3 others | 1,015 MB | ~1,200 MB | — |
| Total | 9,301 MB | ~12,740 MB | WebKit malloc: 6,381 MB |
Two additional problems:
- Zombie processes found: PID 64816 alive for 16 days, PID 28807 alive for 26 days. These sessions ended long ago but the processes never exited.
- Swap nearly full: 24,581 / 25,600 MB used (96%). Swapins: 765M.
Root Cause Hint
WebKit malloc is responsible for 6.3 GB out of 9.3 GB total dirty memory. IOAccelerator (GPU) adds another 2.3 GB. These two categories alone account for 93% of all memory used.
This suggests the WebView layer is not releasing DOM/rendering memory between conversation turns or after context compaction.
Environment
- Claude Code: 2.1.34 (native macOS app)
- macOS: 26.1 (Tahoe, Build 25B78)
- Chip: Apple M3 Pro
- RAM: 18 GB
- Model: Opus 4.6 (1M context)
Steps to Reproduce
- Use Claude Code native for a few hours across multiple sessions
- Run
footprint -p claude --swapped - Observe memory growth and zombie processes
Workaround
pkill -9 claude reclaims all memory.
Related Issues
- [BUG] High memory usage (~13-16 GB) when using Team/Teammate mode #23883 — 13-16 GB in Team mode (Windows, v2.1.34)
- [BUG] Memory leak: API clients created repeatedly instead of reused (8-9 GB memory usage) #22162 — API client leak (macOS, high-priority)
- Claude Code Memory Leak - Process Grows to 120+ GB RAM and Gets OOM Killed #4953 — 120+ GB OOM kill (Linux, oncall)
Activity
github-actions commentedon Feb 8, 2026
Found 3 possible duplicate issues:
This issue will be automatically closed as a duplicate in 3 days.
🤖 Generated with Claude Code
Piesson commentedon Feb 8, 2026
Not a duplicate — this report covers a different version, platform, and trigger from all three flagged issues, and provides new diagnostic data.
What this issue adds that the others don't:
footprintprofiling with malloc zone breakdown — WebKit malloc alone accounts for 6.3 GB out of 9.3 GB dirty. This points directly at the WebView rendering layer, not Node.js or the npm CLI processIf anything, this report strengthens the case that the WebKit malloc leak is a cross-platform, cross-version systemic issue — not limited to one trigger or one version.
Piesson commentedon Feb 25, 2026
Update: Root cause identified — this is a Ghostty terminal bug, not Claude Code
After further investigation, the memory consumption I reported was caused by a memory leak in Ghostty (my terminal emulator), not Claude Code itself.
Root cause: Ghostty has a bug in scrollback pruning where non-standard pages are resized to standard size, causing
munmapto never be called. Claude Code's output (heavy multi-codepoint grapheme sequences) triggers this leak at scale.References:
Status: Fixed on Ghostty's main branch. Will ship in Ghostty 1.3.0 (expected March 2026). Workaround:
scrollback-limit = 2500in Ghostty config.Apologies for the noise — closing this issue.
Piesson commentedon Feb 25, 2026
Closing — root cause is Ghostty memory leak, not Claude Code.
github-actions commentedon Mar 4, 2026
This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.