Tokenizer

Estimate and visualize tokens for current OpenAI and Anthropic models.

Text Input
Enter the text you want to tokenize
Model Selection

OpenAI ยท 1.05M context window

Tokenized Text
Each color represents a different token
TokensCharacters
1056
Lorem ipsum dolor sit amet, consectetur adipiscing elit.

Estimate: This browser-only visualization uses the o200k_base encoding. Exact counts for GPT-6 Astra can differ, especially for structured messages, tools, images, and non-English text. Use the provider's token-counting or usage response for billing and hard context limits.