AI Token Calculator
Paste text to estimate tokens, context-window usage, and API cost for leading GPT, Claude, and Gemini models.
Paste or type your text
How this AI token calculator works
AI models split text into tokens rather than processing only complete words. A token can be a word, word fragment, punctuation mark, number, symbol, or character. This calculator estimates token usage from character mix, punctuation, code density, and CJK characters.
Why the result is an estimate
OpenAI, Anthropic, and Google use different tokenizers. Structured API requests may also add role labels, system instructions, tool definitions, images, or other overhead. For billing-critical work, use the provider’s official token-counting endpoint.
How to reduce token costs
Remove duplicated context, shorten system prompts, retrieve only relevant document sections, cap output length, use prompt caching where available, and route simpler tasks to lower-cost models.
Frequently asked questions
Is this an exact tokenizer?
No. It is a fast browser-based estimator. Exact counts require the tokenizer or counting endpoint for the selected model.
Does it support Various languages?
Yes. Auto mode detects Various languages and other CJK characters and applies a separate estimate.
Does pasted text leave my device?
No. This calculator runs locally and does not send the pasted text to a server.