I built a free extension to track Claude's usage limits before you hit them

If you use Claude daily, you've probably hit a wall mid-task. The reason it's so easy: Claude doesn't have one limit. It has several. A rolling 5-hour session window A weekly pool shared by all models Separate weekly caps per model (Opus, Sonnet, Claude Design) And the weekly pool is sneaky: Fable has no cap of its own and draws that shared pool down ~2× faster than Opus . So you can burn the week without realizing it. I wanted that state visible at a glance instead of digging through settings, so I built Claude Usage Monitor — a small browser extension for Chrome and Firefox. What it does It puts a color-coded % badge in your toolbar , and one click shows the full breakdown: Current 5-hour session + live countdown to reset Weekly all-models pool (with the Fable draw-down flagged on the card) Per-model weekly caps: Opus, Sonnet, Claude Design Daily Claude Code routine runs Extra-usage credits + prepaid balance for pay-as-you-go Auto-detects your plan (Pro / Max 5x / Max 20x / Team), so every number matches your subscription Six themes The privacy part (the part I cared about most) It's open source (MIT) and runs 100% locally — no backend, no analytics, no servers. A design decision I'm happy with: the host permissions are scoped to exactly four claude.ai endpoints (org list, usage stats, routine-run budget, prepaid balance). It physically can't read your chats, projects or files. Narrow permissions = less to trust, and less to exploit. One honest caveat: it reads claude.ai's own usage endpoints, so it can break if Anthropic changes them. Not affiliated with Anthropic. Try it It's free, no account needed (desktop Chrome & Firefox): 🔗 claude-monitor.com Chrome Web Store Firefox Add-ons Happy to hear what else you'd want tracked — drop a comment.