Don't Waste Your Context: Master AI Token Counting
AI models don't read words the same way we do. They break text down into chunks called "tokens." These tokens are the currency of the AI world - they determine how much you pay for an API call and how much information the model can remember at once. Our Token Counter is a free, real-time tool that lets you see exactly how an AI "sees" your prompt.
Why Every Token Counts
Context Windows ("The Brain Limit"): Every AI has a "context window" - the maximum number of tokens it can handle in one go. If your prompt is too long, the AI will start to "forget" the beginning of the conversation. Our tool shows you a progress bar so you know exactly how much room you have left.
API Billing: Whether you're using OpenAI, Anthropic or Google, they charge you based on tokens, not words. A single complex word might be three tokens, while a simple one is just one. Checking your count here before sending a request can save you thousands in unexpected costs.
How We Calculate Your Counts
OpenAI (Exact Results): For models like GPT-4o, GPT-4 and GPT-3.5, we use the official "tiktoken" logic (o200k_base and cl100k_base). These counts are 100% accurate because they use the same code as the OpenAI API itself.
Claude, Gemini & Llama (Smart Approximations): Companies like Anthropic and Google don't release their official tokenizers to the public. For these models, we use a high-precision approximation. For English text, these counts are typically within 5-10% of the actual API result.
| Model | Provider | Context Window | Accuracy |
|---|---|---|---|
| GPT-4o (Incl. mini) | OpenAI | 128,000 tokens | Exact |
| GPT-4 Turbo | OpenAI | 128,000 tokens | Exact |
| Claude 3.5 (Sonnet/Haiku) | Anthropic | 200,000 tokens | Approx |
| Gemini 1.5 (Pro/Flash) | 1,000,000+ tokens | Approx | |
| Llama 3 (70B/8B) | Meta | 128,000 tokens | Approx |
Pro Tips for Prompt Engineering
RAG & Long Documents: If you're building a "Chat with your PDF" app, you need to chunk your data. This tool helps you find the sweet spot where your chunks are small enough to fit but big enough to maintain context.
System Prompts: Your "hidden" instructions count toward the limit too. Use this tool to trim your system prompts so you can give more room to your users' queries.
Cost Control: If you're running millions of API calls, saving even 5 tokens per request can add up to huge savings over time.
Private and Secure
Privacy is mandatory for developers. Your text is never sent to a server, never shared with an AI and never stored in a database. Everything happens right here in your browser using local JavaScript. It's safe for confidential system prompts, sensitive code and proprietary internal documents. No accounts, no logs, just precise counts.