GPT Token Counter
Estimate token count and API cost for GPT-4o, GPT-4, Claude, and Gemini — before you run your prompt.
* Output cost assumes a response equal in length to your input. Actual costs vary.
How to Use the Token Counter
- Select your model from the dropdown — GPT-4o, Claude, Gemini, 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.
Token estimation uses a standard approximation of 4 characters per token for English text, and 1.5 tokens per CJK character. The actual token count from the OpenAI or Anthropic API may differ by 5–10%. For exact counts, use the official tokenizer libraries (tiktoken for OpenAI, tokenizers for Hugging Face).
Key Features
- Multi-model support — covers GPT-4o, GPT-4 Turbo, GPT-3.5, Claude 3.5 Sonnet, Claude 3 Haiku, and Gemini 1.5 Pro.
- 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?
The estimate is accurate to within 5–10% for most English text. The tool uses the widely accepted approximation of 4 characters per token, which OpenAI itself suggests as a quick estimate. For Chinese, Japanese, and Korean text, the tool uses 1.5 tokens per character, reflecting the fact that CJK characters are often split into multiple tokens by current tokenizers. For production systems where exact counts matter, use the official tiktoken library from OpenAI or the tokenizers library from Hugging Face.
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). GPT-4o supports up to 128,000 tokens, Claude 3.5 Sonnet supports 200,000 tokens, and Gemini 1.5 Pro supports up to 1 million tokens. If your prompt plus the expected response exceeds the context window, the API will return an error or truncate the input.