Home / AI context meter for ChatGPT and Claude
AI context meter for ChatGPT and Claude
An AI context meter tells you how full an AI chat's context window is. ContextMeter is a free AI context meter for ChatGPT and Claude, and Gemini support is coming soon.
What does an AI context meter measure?
It estimates the tokens in the visible conversation and shows the percent of the context window used, so you can tell when to start a fresh chat.
How to use it
- Install ContextMeter from the Chrome Web Store.
- Open ChatGPT or Claude. The meter appears in the corner.
- Check the percent and the tokens left.
- Hand off to a fresh chat when you reach red.
ContextMeter is a free Chrome extension (Edge and Firefox to follow) in US English, priced at $0. It runs only in your browser, and your chat text never leaves your computer. Add it to Chrome.
Why people use a context meter
A long ChatGPT or Claude chat gets worse before it hits a hard limit: it forgets early instructions, repeats mistakes and drifts off the task. A meter shows how full the chat is, so you can switch to a new chat at about 50 to 70 percent with a summary, rather than guessing.
Frequently asked questions
What is an AI context meter?
It is a tool that shows how much of an AI model's context window a conversation uses. ContextMeter does this for ChatGPT and Claude in your browser.
Which AI apps does ContextMeter cover?
ChatGPT and Claude today. Gemini support is coming soon, and DeepSeek is planned.
Is ContextMeter free in the US?
Yes. It is free, has no account, and is priced at $0 USD for users in the United States.
Can I count tokens without installing anything?
Yes. The free token counter on this site estimates tokens for any text you paste. It runs in your browser.
Last reviewed 2026-10-08. Numbers change often; see the sources linked on this page.
ContextMeter is a free, private browser extension that shows how full your ChatGPT or Claude chat is while you use it, and helps you carry the chat into a fresh one. See how it works.