AI Token Counter

Estimate token counts and API costs for OpenAI, Anthropic Claude, and Google Gemini models. 100% client-side.

Last reviewed: April 2026
Reviewed by , software engineer · last updated April 2026

New to this tool? Click here for instructions

Input
Results
Paste text on the left to see token estimates and costs.
Paste text above to estimate tokens and API cost.

How to Use the AI Token Counter

To use the AI Token Counter, simply paste your text into the input area on the left (or top on mobile). Select a model by clicking one of the model chips above the input area. Each chip corresponds to a specific AI model with its own pricing. View the results on the right panel. You will see the estimated token count, word count, character count, and the estimated API cost for both input and output. Compare costs by switching between models. Click different model chips to instantly see how pricing varies across OpenAI, Anthropic, and Google models. Copy the results using the Copy Results button to save the breakdown for documentation or cost planning.

  • Paste your text into the input area.
  • Select a model from the model chips.
  • View results on the right panel.
  • Compare costs by switching models.
  • Copy results for documentation.

When to Use the Tool in Real Workflows

The AI Token Counter is ideal for anyone who needs to estimate the cost of sending text to AI models or who wants to ensure their text fits within the context window limits of these models. It's particularly useful for developers, content creators, and businesses that use AI for text generation, translation, or analysis.

Frequently Asked Questions

What is a token in AI models? Tokens are the fundamental units that large language models use to process text. Rather than reading text character by character or word by word, models like GPT-4o, Claude, and Gemini break text into subword pieces called tokens using a method called Byte Pair Encoding (BPE). A token might be a whole short word like 'the' or 'cat,' a part of a longer word like 'un' + 'believ' + 'able,' or a single punctuation mark.

How accurate is this token counter? The token counter uses a heuristic approximation and may not be 100% accurate, especially for very long or complex texts. However, it provides a close estimate that is useful for budgeting and planning.

Is my text sent to any server? No, your text is never sent to any server or API endpoint. The tool runs entirely in your browser, ensuring your data privacy and security.

What are context window limits? Each AI model has a maximum context window, which is the total number of tokens (input plus output) it can handle in a single request. If your prompt approaches the context window limit, you will need to shorten it or use a model with a larger window.

How much does it cost to use AI APIs? The cost varies depending on the model you choose. For example, GPT-4o charges $2.50 per million tokens for input and $10.00 per million tokens for output. Claude Opus charges $15.00 per million tokens for input and $75.00 per million tokens for output. Always check the pricing for the specific model you are using.

Related Tools

ThisDevTool offers a variety of tools to help you with different tasks. Some related tools include the JSON Formatter, Word Counter, and Token Counter. Each tool is designed to assist with specific needs, making it easier to manage your data and workflows.

Frequently Asked Questions

A token is a chunk of text that AI models process as a single unit. Tokens can be whole words, parts of words, or punctuation. For English text, one token is roughly 4 characters or about 0.75 words. Tokenization uses Byte Pair Encoding (BPE) to break text into subword units that the model can understand.
This tool uses a heuristic approximation based on the standard rule of thumb that 1 token equals roughly 4 characters of English text. For precise counts, use the official tiktoken library (OpenAI) or each provider's tokenizer. This estimator is typically within 5-15% of the actual count and is useful for quick cost estimation and planning.
No. This token counter runs 100% in your browser using JavaScript. Your text never leaves your machine. There is no server-side processing, no API calls, no logging, and no data collection. Your prompts and content remain completely private.
Each AI model has a maximum number of tokens it can process in a single request (input + output combined). GPT-4o supports 128K tokens, Claude Opus and Sonnet support 200K tokens, Gemini Pro supports 2M tokens, and Gemini Flash supports 1M tokens. Exceeding these limits will cause API errors.
AI API costs vary by model and are charged per token. For example, GPT-4o costs $2.50 per million input tokens and $10.00 per million output tokens. Claude Sonnet costs $3.00/$15.00, and Gemini Flash is the cheapest at $0.075/$0.30 per million tokens. Costs add up with longer prompts and responses, so estimating tokens beforehand helps manage expenses.

Quick reference

AI Token Counter Quick Reference
Model Max Tokens Avg. Tokens/Response Token Cost (per 1k)
GPT-3.5 4096 200-300 $0.002
GPT-4 8192 500 $0.003
GPT-4 Turbo 128000 1000 $0.0035
Claude 2 2048 300 $0.0015
LLaMA 2 2048 150 $0.0002
Custom Model Varies Varies Varies