Token Monitor — AI Context Tracker

What is Token Monitor — AI Context Tracker?

Token Monitor — AI Context Tracker is a Chrome extension for people using Claude.ai. It adds an in-page overlay and controls on the Claude interface to show how close a conversation is to the model’s context window and how usage quotas may throttle you, so you can avoid cut-off replies or unexpected limit errors.

The extension focuses on real-time visibility: it displays conversation context progress, quota timing (5-hour rolling window and weekly budget), token costs per turn, and warnings when the next message and predicted output are likely to overflow the current context window.

Key Features

• Context window gauge (percentage + token count): Shows how full the current conversation is, helping you anticipate when you may approach the model’s memory limit.
• 5-hour and weekly quota bars with reset estimates: Displays both Claude Pro/Max-style throttling windows in real time and estimates when each quota will reset.
• Truncation risk warning before sending: Calculates whether your next message (plus predicted output) will overflow the context window, then shows an inline banner with suggestions such as splitting the request or starting a new chat.
• Output size prediction near Send: Predicts whether the reply will be categorized as Small, Medium, Large, or XL so you can plan message length.
• Per-turn token cost badges (input/output): Shows token counts for each user message turn, including the input and output token totals.
• Streaming awareness during generation: Tracks tokens committed to the input and tokens streamed back in real time while Claude is generating.
• Self-calibrating token estimates (heuristic): Uses a fast local heuristic (no API calls) to estimate token counts and refines its estimates over time using signals such as “X messages left” banners.

How to Use Token Monitor — AI Context Tracker

1. Install the extension from the Chrome Web Store.
2. Open Claude.ai in Chrome and continue using your existing chat flow—Token Monitor runs only on Claude.ai domains.
3. Use the displayed indicators before sending your next message: check the context gauge, quota bars, and any truncation risk warning near the Send flow.
4. While Claude generates a reply, monitor the streaming-aware token tracking and per-turn token cost badges to understand what was used for that turn.

Use Cases

• Avoiding cut-off replies in long threads: When a conversation is approaching the context window limit, the context gauge and truncation warning help you decide whether to split your request or begin a new chat.
• Managing quota throttling for Pro/Max usage: The 5-hour rolling window and weekly quota bars (with reset estimates) help you plan around throttling windows rather than discovering limits after sending.
• Tuning prompt size based on predicted output: Before submitting, the output size prediction can help you adjust whether you want a shorter answer (e.g., to fit within context) or a more detailed one.
• Budgeting time and tokens during iterative work: Per-turn token cost badges provide input/output token counts for each turn, which can be useful when refining prompts and comparing which turns consume more tokens.
• Using Projects with project knowledge tokens: For conversations inside Projects, the extension includes the relevant “project knowledge token cost” in its context handling.

FAQ

• Does Token Monitor send my conversations to an external server? No. The extension’s processing happens locally in your browser and your conversations are not transmitted to external servers.

• Which sites does the extension run on? It only runs on claude.ai domains.

• How does it estimate tokens and truncation risk? Token counts are estimated via a fast heuristic (not the exact tokenizer). It can self-correct over time using signals such as “X messages left” banners.

• Do I need an account or login to use it? No account creation or login is required.

• Which Claude plans and models are supported? The extension is described as working with Claude Free, Pro, Max (including 5x and 20x), Team, and Enterprise, and with models available on Claude.ai (Sonnet, Opus, Haiku).

Alternatives

• Built-in Claude usage indicators (account dashboard/settings): Claude’s own quota and settings pages provide official quota information, but they may not include per-turn token cost badges or an inline truncation warning in the chat UI.
• Other context/truncation helper extensions (chat UI overlays): Extensions that add token counting or message length checks can provide similar “before you send” guidance, though their accuracy and scope may differ.
• Manual prompt shortening and session resets: For users who prefer not to install extensions, a workflow of shorter messages and periodically starting new chats can reduce the risk of hitting context limits, but it lacks real-time gauge and quota visualization.
• Developer-side token management tooling: If you integrate prompts into an application, you can manage token budgets in your own tooling; this is different from an in-browser overlay and may require engineering effort.