ContextMeter: AI Context & Token Counter — ContextMeter

ContextMeter shows how much of the AI context window your current chat has used, so you know when to start fresh before answers get worse.

What you get
- A small meter on ChatGPT and Claude with the percent used, color-coded green, amber and red.
- A details panel: estimated tokens, room left, and which messages take the most space.
- Honest labels: every number is an estimate of the visible messages, and it says so.
- Handoff: ask the AI for a structured summary, then continue in a fresh ChatGPT or Claude chat with one click. You press Send yourself.
- Draft preview: see what an unsent paste would cost before you send it.
- Works on long chats: Claude removes older messages from the page as you scroll, so ContextMeter remembers what it has seen and offers a full-chat scan.
- Settings for your plan or a custom limit, warning levels, theme and position. Keyboard shortcut: Alt+Shift+M.

Private by design
Everything runs on your device. No account, no analytics, no servers, no network requests. Chat text is never stored; only chat titles, message ids and token counts are kept on your device.

Good to know
- Counts are estimates: they cover visible message text, not system prompts, memory, tool output, hidden reasoning or attachments.
- Context limits vary by plan and change often. ChatGPT starts on the Free plan; check yours in Settings.
- ContextMeter is not affiliated with OpenAI or Anthropic.