About This Tool
Estimate how many tokens your text uses across popular AI models including GPT-4, Claude, Llama, Gemini, Mistral, and DeepSeek. Compare context window usage and plan your prompts effectively. All processing happens locally in your browser — your text is never sent to any server.
How to Use
Paste or type your text into the input area.
Select an AI model to see the estimated token count.
View the context window usage bar to understand how much of the model's capacity your text uses.
Switch to the Compare tab to see token estimates across all supported models side by side.
Frequently Asked Questions
How accurate are these token estimates?
These are approximate estimates based on character-level heuristics (average characters per token). Actual token counts depend on each model's specific tokenizer. For precise counts, use official tools like OpenAI's tiktoken or Anthropic's token counter.
Why do different models produce different token counts?
Each AI model uses a different tokenizer with its own vocabulary. Some tokenizers are more efficient at encoding certain languages or code patterns. For example, models trained on more code data may tokenize programming languages more efficiently.
What is a context window?
The context window is the maximum number of tokens a model can process in a single request (input + output combined). For example, GPT-4 Turbo has a 128K token context window, while Claude 4 supports up to 200K tokens.
Does this tool send my text anywhere?
No. All token estimation happens entirely in your browser using JavaScript. Your text never leaves your device.