Token Counter API — Count Tokens in Text for LLM Processing
Count tokens in any text for LLM context window management. Estimate tokens for OpenAI, Anthropic, and other AI models. Free API.
What is Token Counting?
Token counting estimates how many tokens a piece of text contains. Tokens are the basic units that language models process, roughly equivalent to 0.75 words for English text. The API estimates tokens using a character-based heuristic that provides fast, approximate counts without requiring a full tokenizer.
How to Use It
Call GET /api/v1/token-counter?input=Hello+world+this+is+a+test. Returns { tokens: number, characters: number, words: number, tokens_per_word: number, model_estimate: string }.
Try it live
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Frequently Asked Questions
How accurate is the token count?
The estimation is approximately ±10% accurate for English text. For exact token counts, use the tokenizer for your specific model (cl100k_base for GPT-4, p50k_base for older models).