Claude Token Counter
Estimate token usage for your CLAUDE.md, system prompt, or any text. See how your content fits in Claude's context window — runs entirely in your browser, no data sent anywhere.
Estimated tokens
0
≈ 4 chars per token (English prose)
Context window usage
Tips for reducing tokens
- Remove redundant comments and examples
- Use bullet points instead of prose
- Keep code snippets short and focused
- Browse lean community rules for inspiration
Find lean CLAUDE.md rules
Browse community-optimized rules that balance context and effectiveness.
Browse rulesWhat is a Claude token?
Claude uses a byte-pair encoding (BPE) tokenizer similar to GPT models. Roughly speaking, one token is about 4 characters of English prose or 3 characters of code. A word like "tokenization" counts as 2–3 tokens. The Claude API bills by token — both input (prompt) and output (response).
What is a context window?
The context window is the maximum number of tokens Claude can process in a single request. Claude Haiku 4.5, Sonnet 4.6, and Opus 4.6 all support 200,000 tokens (~150,000 words). If your prompt plus expected output exceeds this limit, you will need to shorten your input.
Tips for reducing token count
- Remove redundant comments and examples from CLAUDE.md
- Use bullet points instead of prose paragraphs
- Keep code snippets short and focused — show patterns, not full implementations
- Avoid repeating the same instruction in multiple ways
- Browse lean community rules for inspiration