GPT Token Counter
Estimate token count and API cost for GPT-5.6, Claude, and Gemini — before you run your prompt.
Note: Claude Sonnet 5 at $2 / $10 is introductory pricing through 2026-08-31, after which it returns to $3 / $15. Check each vendor's own pricing page (figures here checked 2026-08-02).
* Output cost assumes a response equal in length to your input. Actual costs vary.
Pricing verified 2026-07-19 from official pricing pages (OpenAI / Anthropic). Claude Sonnet 5 is at introductory pricing of $2 / $10 through 2026-08-31, returning to $3 / $15 on 2026-09-01. The GPT-5.6 figures above are standard rates (input ≤ 272K tokens); for requests over 272K input tokens OpenAI bills the whole request at 2× input and 1.5× output, which this tool does not apply. Prices change — always confirm on the official page before budgeting.
How to Use the Token Counter
- Select your model from the dropdown — GPT-5.6, Claude, or others.
- Paste your prompt into the text area. The token estimate updates instantly.
- Review the estimated token count and API cost for both input and output.
- Click Copy Estimate to save the summary to your clipboard.
This tool uses a rough approximation (not an exact tokenizer): about 4 characters per token for English (i.e. estimated tokens ≈ English characters ÷ 4), and about 1.5 tokens per CJK character. It is a quick estimate, not the precise output of each provider's tokenizer — different models use different tokenizers (newer models may split the same text into noticeably more tokens; the exact increase depends on the content — check each provider's docs), and code, punctuation, and special characters push the error higher. The error can be substantial and varies by model and content. For exact counts (billing or context planning), use the official tools: tiktoken for OpenAI, or Anthropic's official token-counting endpoint.
Key Features
- Multi-model support — covers GPT-5.6 Sol / Terra / Luna, Claude Opus 4.8, Claude Sonnet 5, and Claude Haiku 4.5.
- Live cost estimation — see input and output costs in USD as you type.
- CJK-aware tokenization — handles Chinese, Japanese, and Korean text differently from Latin scripts.
- No API key required — all estimation happens client-side.
- Free forever — no sign-up, no limits.
Frequently Asked Questions
What is a token in AI language models?
A token is the basic unit of text that AI language models process. Tokens are not the same as words or characters — they are chunks of text that the model's tokenizer splits your input into before processing. In English, one token is roughly 4 characters or 0.75 words. Common words like "the" or "is" are usually one token, while longer or rarer words may be split into multiple tokens. Understanding tokens matters because API pricing is based on token count, and models have maximum context windows measured in tokens.
How accurate is this token estimate?
This is an estimate, not an exact count. The error can be substantial and varies with the model and content, so no fixed error percentage is guaranteed. Newer models use newer tokenizers that may split the same text into noticeably more tokens (the exact increase depends on the content — check each provider's docs), and CJK characters, code, and heavy punctuation increase the error further. The tool uses about 1.5 tokens per CJK character as a rough figure. For production systems where exact counts matter, use OpenAI's tiktoken library or Anthropic's official token-counting tool.
Are the pricing figures up to date?
Pricing is based on publicly available rates as of mid-2026. AI model pricing changes frequently as providers compete and scale their infrastructure. Always verify current pricing on the official pricing pages of OpenAI, Anthropic, and Google before making budget decisions. This tool is intended for rough estimates and planning, not for billing calculations.
What is a context window?
The context window is the maximum number of tokens a model can process in a single API call, including both your input (prompt) and the model's output (response). Limits differ by model — for example, Claude Opus 4.8 and Claude Sonnet 5 offer a context window of up to 1 million tokens per Anthropic's official docs; check each provider's documentation for other models. If your prompt plus the expected response exceeds the context window, the API will return an error or truncate the input.