AI Prompt Token Counter (Approx)

Estimate a prompt’s token count

Models measure and price text in tokens, not words or characters, and knowing a prompt’s token count matters for cost and context limits. This tool approximates token counts for GPT, Claude and Gemini-style tokenizers using a heuristic estimate.

Why tokens, and why approximate

A token is roughly a word-piece, and models count them to price requests and enforce context limits, so the token count of a prompt determines both what it costs and whether it fits. The exact count depends on the specific tokenizer, which differs between model families and is not something a simple tool reproduces precisely. A good heuristic, based on the general relationship between characters, words and tokens, gets close enough for budgeting and fit-checking. Treat the result as a solid estimate for planning, not the exact figure the model will bill, which only the model’s own tokenizer gives.

Close enough to plan

The tool runs entirely in your browser, so nothing you paste, prompts, outputs or documents, is uploaded, which matters when the input is sensitive AI data or your own content.

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