AI Token Counter
Count tokens for GPT-4o, Claude, and Gemini models instantly.
Reviewed by Aygul Dovletova · Last reviewed
How to Use the AI Token Counter
- Paste or type your text into the input area.
- Click Count Tokens.
- Read the per-model breakdown in the results table below.
What It Does
The AI Token Counter runs entirely in your browser. GPT-4o token counts use the cl100k_base BPE encoder via the gpt-tokenizer library loaded on demand - no data is sent to any server. Claude and Gemini estimates use a character-based formula (chars divided by 3.5) that is accurate to within roughly 10% for English text. Use this tool to check prompt length before hitting API limits or to estimate API costs.
Frequently Asked Questions
How are tokens counted for GPT-4o?
GPT-4o uses the cl100k_base BPE encoding. This tool runs the same encoder client-side via gpt-tokenizer, so the count matches what OpenAI's API reports.
Why are Claude and Gemini counts approximate?
Anthropic and Google do not publish client-side tokenizer packages. The tool uses a character-based estimate (chars / 3.5 for English) which is within roughly 10% for typical prose. For precise counts use the provider's API.
Is my text sent to any server?
No. All tokenization runs in the browser tab. There is no fetch call.
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