NEW301688
Web Inspector: Huge memory leak when devtools open 
https://bugs.webkit.org/show_bug.cgi?id=301688
Summary Web Inspector: Huge memory leak when devtools open
Jozef
Reported 2025-10-30 05:13:22 PDT
Created attachment 477230 [details] video evidence Safari consumes 48GB+ of RAM when using `@csstools/css-tokenizer` to parse CSS. Issue occurs ONLY when DevTools is open. Page becomes unresponsive. Chrome/Firefox work fine. Environment Safari: Latest (macOS 26.0.1) — also tested with Safari 18 and 17; the same issue occurs there via BrowserStack. Extensions: No extensions enabled Reproduction Live Demo: https://safari-memory-leak.vercel.app Repository: https://github.com/Joozty/safari-memory-leak Quick Test (Live Demo) 1. Open https://safari-memory-leak.vercel.app in Safari 2. Open DevTools - Required to trigger the bug 3. Reload page 4. Memory spikes to 48GB+, page fails to reload Video Evidence - Normal window: https://github.com/Joozty/safari-memory-leak/raw/refs/heads/main/public/normal.mp4 - Incognito window: https://github.com/Joozty/safari-memory-leak/raw/refs/heads/main/public/incognito.mp4
Attachments
video evidence (1.96 MB, video/mp4)
2025-10-30 05:13 PDT, Jozef 		no flags
Details
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Anuj Panta
Comment 1 2025-10-30 17:48:30 PDT
After some investigation we found that opening the timeline tab within the WI and running this actually lets the the tokens parse, it seems when other tabs are open and we try the full payload we see a large memory issue
Radar WebKit Bug Importer
Comment 2 2025-11-06 04:14:11 PST
<rdar://problem/164162234>
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