ContextMeter: AI Context & Token Counter by 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.