AI Token Counter

The AI Token Counter estimates how many tokens a piece of text may use and reports related text metrics. Paste text, choose a model profile, and review estimated tokens, words, characters, sentences, lines, paragraphs, token density, and context-window usage.

What the calculator measures

The counter uses a transparent heuristic rather than a provider tokenizer. It estimates tokens from both character count and word count:

$\text{Character estimate} = \frac{\text{Characters}}{4}$ $\text{Word estimate} = \frac{\text{Words}}{0.75}$ $\text{Estimated tokens} = \max\left(\text{Words},\operatorname{round}\left(\frac{\text{Character estimate}+\text{Word estimate}}{2}\right)\right)$

The result is compared with the selected model's stored context-window size. Context usage (%) is estimated tokens divided by that window, multiplied by 100.

Example

For a short 40-word paragraph containing 160 characters:

1. Character estimate: 160 / 4 = 40.
2. Word estimate: 40 / 0.75 = 53.3.
3. Combined estimate: (40 + 53.3) / 2 = 46.7, rounded to about 47 tokens.

The counter also reports the exact JavaScript character length, whitespace-delimited word count, detected sentence count, line count, and paragraph count used by the implementation.

Context-window interpretation

If the estimated token count is greater than the selected model profile's context window, the result is marked over the limit. A result below the limit is not a guarantee: chat wrappers, system instructions, tool definitions, images, and provider-specific tokenization can add usage that is not present in pasted text.

For API budget estimates, use the LLM API Cost Calculator. For a direct token-to-word estimate with adjustable ratios, use the Tokens to Words Converter.

Questions

Is this token count exact?

No. It is a heuristic based on characters and whitespace-delimited words. Exact counts require the tokenizer used by the target model.

Which text is included?

Only the text pasted into the counter is measured. Hidden prompts, message roles, system instructions, tool schemas, and uploaded media are not included.

What does context percentage mean?

It is the estimated token count divided by the selected model profile's context-window size. It is a planning signal, not a provider guarantee.

Privacy and limitations

The calculation runs locally in the browser. The tool does not send pasted text to an API, but the estimate can differ for code, punctuation-heavy text, non-English languages, and text containing unusual Unicode characters.