AI Token Counter and Cost Calculator 2026

An AI token is the basic unit that language models use to process text. In English, one token is roughly 4 characters or 0.75 words. The word 'tokenization' becomes 3 tokens; punctuation and spaces count separately. Token limits determine how much text a model can process in a single request, which directly affects both what you can ask and what it costs to ask it.

This token counter runs entirely in your browser using the same tokenization logic as the models themselves. Paste any text, a prompt, a document, a system message, and see character counts, word counts, estimated tokens for GPT-4o, Claude Sonnet, Gemini 2.5, and GPT-4 Turbo simultaneously. Use it before API calls to avoid context-exceeded errors and to optimize prompt length before deploying to production.

GPT-4o costs $2.50 per 1 million input tokens and $10.00 per 1 million output tokens as of June 2026. For most users running short prompts, this works out to fractions of a cent per request. The cheapest major model is Gemini Flash at $0.075 per 1 million input tokens, making it about 33 times cheaper than GPT-4o for input.

For context, a 1,000-word document contains roughly 1,300 to 1,500 tokens. At GPT-4o input pricing, that costs around $0.003 to $0.004 per document. Claude Sonnet 4.6 runs slightly higher at $3.00 per 1 million input tokens but offers a 200,000 token context window versus GPT-4o at 128,000 tokens.

For a side-by-side breakdown, try the OpenAI API cost calculator or the Claude API pricing calculator.

1,000 words is approximately 1,300 to 1,500 tokens in standard English. The rule of thumb is 1 token per 4 characters or about 0.75 words per token. Technical content with code, numbers, or special characters tends to tokenize higher because those elements often split into multiple tokens.

Each AI model uses a different tokenizer, so the same text produces slightly different counts. GPT-4o uses OpenAI's tiktoken library. Claude uses its own byte-pair encoding. Gemini uses SentencePiece. The differences are usually small for English text but can be more noticeable for non-Latin scripts or code-heavy prompts.

Gemini Flash at $0.075 per 1 million input tokens is currently the cheapest major model for most tasks as of June 2026. GPT-4o mini ($0.15 per 1M) and Claude Haiku 4.5 ($0.80 per 1M) are also affordable options for high-volume applications where cost per token matters more than raw capability.

For output tokens, the gap between models widens. Gemini Flash charges $0.30 per 1 million output tokens while o1 charges $60.00. If your use case generates long outputs, choosing the right model matters more than on the input side. The cost table above shows the full comparison for each model.