Claude Monitor shows how much Claude you have left before you hit a usage limit. A badge in your browser toolbar tracks your 5-hour session and weekly limit live, with a countdown to every reset and desktop alerts at 80% and 95%. One click opens per-model weekly caps, extra-usage credits, Claude Code routine runs and 30 days of history you can export.

It also works on the Free plan: since August 2026 claude.ai shows no usage to Free accounts, so the extension reads the limits attached to each reply instead. New in 1.21: the optional bar above the chat box also shows up in claude.ai's new interface and in Claude Code on the web, plus a pace forecast.

How it is built: a Manifest V3 extension for Chrome, Firefox and Edge, in plain JavaScript with no build step. It only talks to claude.ai, with read-only requests for your usage data. The bar's page scripts use optional permissions, requested only when you turn the bar on.

Free, open source (MIT), no account, no telemetry. The only data the project receives is an optional uninstall survey. Not affiliated with Anthropic.