AI & LLM · Client-side
AI Token Counter
Paste any prompt or text to see estimated token counts across GPT-4o, Claude, and Gemini, with context window usage and cost estimates per request.
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Characters
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Words
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Lines
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Avg tokens (GPT)
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Avg tokens (Claude)
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Avg tokens (Gemini)
Model Breakdown
GPT-4o
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tokens
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Input cost
$2.50/1M
Rate
GPT-4o mini
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tokens
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Input cost
$0.150/1M
Rate
Claude 3.5 Sonnet
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tokens
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Input cost
$3.00/1M
Rate
Claude 3 Haiku
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tokens
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Input cost
$0.250/1M
Rate
Gemini 1.5 Pro
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tokens
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Input cost
$1.25/1M
Rate
Gemini 1.5 Flash
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tokens
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Input cost
$0.075/1M
Rate
Estimates only. Token counts are approximated using a BPE heuristic and may differ from official tokenizers by ±10–15%. Costs are based on publicly listed prices and may not reflect volume discounts, cached tokens, or recent pricing changes. For billing-accurate counts, use the official APIs.
What is a token?
Tokens are the chunks text is split into before processing. A token is roughly 4 characters or ¾ of a word in English. Code, punctuation, and non-Latin scripts tokenize differently.
Context windows
The context window is the maximum number of tokens a model can process in one request, both your input and the output combined. Exceeding it causes content to be truncated.
Cost tip
Input tokens are charged differently from output tokens, usually 3–5× cheaper. Cached prompt tokens (Claude, GPT-4o) can be 75–90% cheaper on repeated calls.
AI Token Counter — Frequently Asked Questions
01Why do token counts differ between GPT, Claude, and Gemini?+
Each model uses a different tokenizer. GPT-4o uses the cl100k_base tokenizer (tiktoken). Claude uses its own BPE tokenizer. Gemini uses SentencePiece. The same text tokenizes to a different count depending on the vocabulary and merge rules — usually within 5–15% of each other, but the gap widens with code, non-English text, and special characters.
02What is a context window and why does it matter?+
The context window is the maximum number of tokens a model can process in a single request — including your prompt, conversation history, and the model's response. If your input exceeds the window, the model truncates earlier content silently. GPT-4o has a 128K token context. Claude 3.5 Sonnet has 200K. Knowing your token count before sending prevents silent truncation.
03How accurate are the cost estimates?+
Estimates are based on publicly listed input token prices at the time the tool was last updated. Actual costs also include output tokens, which vary. Use these figures as planning estimates — check each provider's current pricing page for billing decisions.
04Can I count tokens for a full document or long system prompt?+
Yes. Paste any text — a system prompt, a full document, a conversation transcript, or a code file. The counter handles large inputs and shows you exactly how much of each model's context window you are consuming as a percentage.
05Is my text sent anywhere?+
No. Token counting runs entirely in your browser using local tokenizer implementations. Nothing you paste is transmitted to any server. The tool works offline once loaded.