API-accurate counts
Uses Anthropic's messages.count_tokens endpoint — the same logic used for billing and context limits.
Free · No account · claudetokenizer.online
Claude Tokenizer
Count tokens for Claude models using the official Anthropic API. Paste text, pick a model, and see input tokens instantly.
Input tokens—
Why use this tool
Latest Claude models
Sonnet, Opus, and Haiku 4.x plus Claude 3.5 Sonnet. Switch models to compare token usage.
Privacy-first
Text is sent only to count tokens on our server. We do not store your prompts.
Multi-language
Interface available in English, Chinese, Japanese, Korean, Spanish, German, French, and Portuguese.