Cloken: A Chrome Extension That Shows Real-Time Claude Context Usage as a Percentage

Cloken is a lightweight Chrome extension that adds a small, unobtrusive widget to your claude.ai browser session. It counts all context elements in a chat — every message, uploaded file, image, and even the system prompt — and displays the total usage as a percentage of the context window. The tool was built by a Reddit user (u/SumDoodWiddaName) who has been using it for weeks and reports that seeing context fill up in real time is eye-opening.

Key features according to the source:

• Shows a percentage of context used in the current Claude.ai chat.
• Counts all messages, uploaded files, images, and system prompt.
• Tiny, unobtrusive widget in the corner of the browser.
• Helps identify when context is getting unmanageable and when to start a new chat.
• Free to use — no data collection, no sales.
• Open-ended project; author welcomes bug reports and feature requests.

The creator emphasizes that the extension does not solve the problem of running out of usage or sudden quality degradation. What it does provide is awareness — a concrete, real-time number so you know exactly how much of the context window is consumed. This addresses a common pain point for developers who notice response quality dropping but can't pinpoint why.

For developers who use Claude heavily — especially with long conversations, code files, or image attachments — this tool offers a practical way to monitor context limits without guessing.