What is a token in LLMs?

A token is a chunk of text that an LLM processes as a single unit. In English, one token is roughly 4 characters or ¾ of a word. For example, 'ChatGPT' is 2 tokens and 'tokenization' is 3 tokens. LLMs have a maximum context window defined in tokens — so counting them matters for both cost and functionality.

How accurate is this token counter?

This tool uses a BPE (Byte Pair Encoding) approximation that closely matches OpenAI's cl100k_base tokenizer used by GPT-4 and GPT-3.5. For Claude and Llama models, we use a comparable approximation. Real counts can vary by ±2–5% depending on the model's exact vocabulary — for precise counts, use the model provider's official tokenizer API.

What models are supported?

We support GPT-4o, GPT-4 Turbo, GPT-3.5 Turbo, Claude 3 Opus, Claude 3 Sonnet, Claude 3 Haiku, Llama 3 (70B/8B), and Gemini 1.5 Pro. Each model has different context window sizes and pricing, which are reflected in the results.

How is the API cost calculated?

Costs are estimated based on the input token pricing for each model as of mid-2025 (e.g., GPT-4o at $5/1M input tokens). These are estimates only — actual costs depend on your provider's current pricing, output tokens, and any applicable discounts or batching. Always check the provider's pricing page for the latest rates.

Is my text sent to any server?

No. All processing happens entirely in your browser — your text never leaves your device. This tool requires no backend, no login, and no API keys. Your prompts and data stay private.

Free LLM Token Counter

Count Tokens for
GPT-4, Claude & More

Paste any text and instantly see how many tokens it uses across popular LLM models — plus context window fill percentage and estimated API cost.

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Multi-Model Support

Estimate tokens for GPT-4o, GPT-3.5, Claude 3 Opus/Sonnet/Haiku, Llama 3, and Gemini Pro.

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Context Window Fill

See exactly what percentage of a model's context window your prompt occupies — avoid hitting limits.

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API Cost Estimate

Get an instant cost estimate for your text as input tokens based on current pricing for each model.

Model

Tokens

Words

Characters

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Est. cost

Context window fill — GPT-4o0 / 128,000 tokens

Frequently Asked Questions

Everything you need to know about Token Counter.

Count Tokens forGPT-4, Claude & More

Multi-Model Support

Context Window Fill

API Cost Estimate

Frequently Asked Questions

Count Tokens for
GPT-4, Claude & More