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AI Token Counter

Estimate by
Estimated tokens —
Characters
—
Words
—
Tokens by character rule
—
Tokens by word rule
—
Share of context window
—
Tokens left in window
—

Paste your prompt and the counter estimates its tokens with OpenAI's rules of thumb: about 4 characters of English per token, or 100 tokens per 75 words. A 75-word paragraph comes to roughly 100 tokens, under 0.1% of a 128,000-token context window. Chinese, Japanese and Korean characters count as about one token each.

About this tool

Language models bill and limit by tokens, not words, so a prompt that looks short can still overflow a context window or cost more than planned. This counter gives a quick estimate while you type. It applies two published rules of thumb, characters divided by four and words divided by 0.75, and lets you pick either one or their average. Next to the estimate it shows how much of your context window the text fills, how many tokens remain, and a per-paragraph breakdown so you can see which section to trim. The limit is plain: it is an estimate, not a real tokenizer. Exact counts depend on each model's vocabulary, and code, numbers and non-English text can differ from the estimate by a wide margin. Your text stays in the browser.

How to use it

  1. Paste the text

    Type in the box, paste a prompt, or open a .txt or .md file from your device.

  2. Pick the rule

    Choose characters ÷ 4, words ÷ 0.75, or the average of the two.

  3. Set the context window

    Enter the model's window in tokens, for example 8,000 or 128,000, to see the share used and tokens left.

  4. Check the paragraph table

    Find the longest paragraphs by estimated tokens before cutting a prompt to fit.

Examples

75 words, word rule

Your prompt or text
word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word
Estimate by
Words ÷ 0.75
Context window
128000

Result Estimated tokens: 100
Characters: 374
Words: 75
Tokens by character rule: 94
Tokens by word rule: 100
Share of context window: 0.08%
Tokens left in window: 127,900

  1. Character rule: 0 CJK characters + 374 other characters ÷ 4 = 93.5 tokens.
  2. Word rule: 75 words ÷ 0.75 = 100 tokens.
  3. Estimate used (words): 100 tokens, 0.08% of a 128000-token window.

OpenAI's guide puts 75 English words at about 100 tokens, and the word rule reproduces that exactly.

A one-line pangram, averaged

Your prompt or text
The quick brown fox jumps over the lazy dog.
Estimate by
Average of both
Context window
8000

Result Estimated tokens: 12
Characters: 44
Words: 9
Tokens by character rule: 11
Tokens by word rule: 12
Share of context window: 0.15%
Tokens left in window: 7,988

  1. Character rule: 0 CJK characters + 44 other characters ÷ 4 = 11 tokens.
  2. Word rule: 9 words ÷ 0.75 = 12 tokens.
  3. Estimate used (blend): 12 tokens, 0.15% of a 8000-token window.

44 characters give 11 tokens and 9 words give 12; the average of 11.5 rounds to 12.

Four Chinese characters

Your prompt or text
你好世界
Estimate by
Characters ÷ 4
Context window
128000

Result Estimated tokens: 4
Characters: 4
Words: 2
Tokens by character rule: 4
Tokens by word rule: 3
Share of context window: 0%
Tokens left in window: 127,996

  1. Character rule: 4 CJK characters + 0 other characters ÷ 4 = 4 tokens.
  2. Word rule: 2 words ÷ 0.75 = 2.7 tokens.
  3. Estimate used (chars): 4 tokens, 0% of a 128000-token window.

Chinese characters are counted as about one token each, so this greeting comes to 4 tokens rather than 1.

How it is calculated

tokens ≈ CJK characters + other characters ÷ 4, or tokens ≈ words ÷ 0.75

characters
user-perceived characters (graphemes), including spaces and punctuation
words
runs of Unicode letters or digits
0.75
average words per token in English text, from OpenAI's guidance

OpenAI's help article on tokens states that one token is about 4 characters of English and that 100 tokens is about 75 words. The character rule divides the character count by four, except that Chinese, Japanese and Korean characters are counted as roughly one token each, since byte-pair tokenizers rarely merge them. The word rule divides words by 0.75. The average option takes the mean of the two. The share of the context window is the estimate divided by the window size you enter.

When not to use it

  • When a request must fit a hard limit to the last token, run the provider's own tokenizer instead.
  • For source code, long numbers or minified data, where token counts diverge sharply from the 4-characters rule.

Common mistakes

  • Forgetting that the model's reply also uses the context window, not only the prompt.
  • Assuming every model splits text the same way; Claude, GPT and Gemini tokenizers give different counts.
  • Ignoring system prompts and chat history, which count toward the window as well.

Frequently asked questions

Why is this an estimate and not an exact count?

Exact counts need the model's tokenizer vocabulary, which is a large file and differs between providers. The rules used here track English prose closely, typically within about 10 to 15 percent, but they are not a substitute for the provider's tokenizer when a limit is tight.

Which rule should I pick?

For ordinary English prose the two rules land close together. The character rule handles text with long or unusual words better, while the word rule suits plain conversational writing. The average smooths out both and is a reasonable middle choice for planning.

Why do Chinese and Japanese count so many tokens?

Tokenizers are trained mostly on English, so a single CJK character is usually its own token or even split into several. Counting one token per character is closer to reality than dividing by four, though some characters still cost two or three tokens.

How big is a typical context window?

Windows range from about 8,000 tokens on older models to 128,000, 200,000 or over a million on recent ones. Check your model's documentation and enter that figure; the counter then shows the share used and the tokens left for the reply.

Do spaces and punctuation count as tokens?

They count toward the character total, so they affect the character-rule estimate. In real tokenizers a leading space is usually merged into the following word, while punctuation marks often become tokens of their own.

Is my prompt sent to an AI service?

No. The estimate is worked out in your browser from character and word counts, and no model or server sees the text you paste.

Cite this tool

Using this tool in an assignment, article or report? Copy a citation, or a link for your website.

APA

Tools Directory Editorial Team. (2026, October 25). AI Token Counter. Tools Directory. Retrieved October 26, 2026, from https://tools.milunir.com/text-tools/ai-writing-assistants/ai-token-counter/

MLA

Tools Directory Editorial Team. “AI Token Counter.” Tools Directory, 25 Oct. 2026, https://tools.milunir.com/text-tools/ai-writing-assistants/ai-token-counter/. Accessed 26 Oct. 2026.

Chicago

Tools Directory Editorial Team. “AI Token Counter.” Tools Directory. Last modified October 25, 2026. Accessed October 26, 2026. https://tools.milunir.com/text-tools/ai-writing-assistants/ai-token-counter/.

Link<a href="https://tools.milunir.com/text-tools/ai-writing-assistants/ai-token-counter/">AI Token Counter – Tools Directory</a>