Prompt Token Counter
Estimate token counts for your AI prompts. Works with GPT-4, Claude, Llama, and all major models. Check context window usage and get character, word, and line statistics instantly.
Write your prompt here
Token count by model
19 models| Model | # Tokens |
|---|---|
GPT-5.5, GPT-5.4, GPT-5.4 mini OpenAI1M ctx | 0 tokens |
GPT-5, GPT-5 Mini, GPT-5 Nano OpenAI128K ctx | 0 tokens |
o4 Mini, o3, o3 Mini OpenAI200K ctx | 0 tokens |
GPT-4.1, GPT-4.1 Mini, GPT-4.1 Nano OpenAI1M ctx | 0 tokens |
Est. Tokens
0
Characters
0
No-space chars
0
Words
0
Lines
0
Sentences
0
Context window usage
Token Visualization
Understanding Tokens
What is a token?
AI language models don't process text word by word — they process it as tokens. A token is a chunk of text, usually 2–6 characters for common English words. Short words like "the" or "is" are often one token; longer words like "tokenization" split into multiple tokens.
As a rule of thumb, 1 token ≈ 4 characters in English. 100 tokens ≈ 75 words. This is the heuristic used by this tool and documented by OpenAI.
Why do tokens matter?
- 1. Cost: AI APIs charge per token. Knowing your count before calling saves money.
- 2. Context limit: Every model has a maximum context window. Exceeding it causes API errors or truncated output.
- 3. Response space: The window is shared between your prompt and the model's response — large prompts leave less room for answers.
Context Window Reference
| Window | Max Tokens | Example Models |
|---|---|---|
| 8K | 8,192 | GPT-4, GPT-3.5 Turbo |
| 128K | 128,000 | GPT-4o, GPT-5, Gemma 3, Llama 3.3 |
| 200K | 200,000 | Claude Haiku 4.5, Grok 3 |
| 1M | 1,000,000 | Claude Opus 4.8/4.7, Sonnet 4.6, GPT-4.1, Llama 4, Gemini 3 Flash |
| 2M | 2,000,000 | Gemini 2.5 Pro/Flash, Gemini 3.1 Pro, Gemini 3.5 Flash |
Pages at ~250 words/page · 1 token ≈ 0.75 words · limits may vary by model version.