AI models don't read words, they read tokens: chunks of text that are often part of a word. Tokens decide how much you can paste into ChatGPT, Claude, Gemini or Grok at once (the "context window"), and they're how API usage is billed. This free AI token counter gives you a quick estimate of how many tokens your text uses, checks it against common context window sizes, and estimates API cost at whatever price per million tokens you enter. To be upfront: this is an estimate. Each company uses its own tokenizer, and we don't load any of them, so the tool doesn't send your text anywhere. For typical English, the estimate is usually within about 10 to 15% of the real count. Code, numbers and non-English text can differ more.
Estimate tokens
Will it fit?
Estimate only: we average two common rules of thumb (about 4 characters per token, and about 0.75 words per token for English). Check your AI provider's own tokenizer or pricing page for exact numbers. Context sizes below are common tiers, not exact limits for a specific model.
How to use the token counter
- Paste your prompt, document or chat history.
- Read the estimated tokens. Remember the AI's reply uses tokens too.
- Check the table to see roughly what context size you need.
- For API projects, enter your model's input price from the provider's pricing page to estimate cost.
Tokens in plain English
For English text, 1,000 tokens is roughly 750 words, or about one and a half pages. A 300-page book is around 100,000 to 130,000 tokens. Short common words like "the" are usually one token, while long or rare words split into several. If you're comparing what different AI apps cost on a monthly plan rather than the API, try our AI subscription cost calculator.
FAQ
How accurate is this token counter?
It’s an approximation. For ordinary English prose it’s usually close, but each model family (OpenAI, Anthropic, Google, xAI) has its own tokenizer, so exact counts differ. Use the provider’s official tokenizer when precision matters.
Why not use the real tokenizer?
Official tokenizers are large files, and some aren’t public. Keeping this tool lightweight and fully in-browser means your text never leaves your device.
Do output tokens cost more?
Usually, yes. Most AI APIs charge more per output token than per input token. This tool estimates input only.
What is a context window?
It’s the maximum number of tokens a model can consider at once, including your prompt, any files and its reply. If you go over, older text is cut off or the request fails.
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