Free AI Token Counter & Estimator

What are tokens in AI?

Tokens are the units AI models use to read and generate text—roughly word pieces or subwords. One token is often 3–4 characters in English, but punctuation, emojis, and other languages can use more or fewer characters per token. This GPT token calculator estimates how many tokens your prompt uses so you can stay within the model's context window.

Why token limits matter

Every model has a maximum context size (e.g. 128K for GPT-4 Turbo). Your input and the model's output together must fit. Exceeding the limit causes errors or truncation. Use this ChatGPT token calculator before sending long prompts or when you need to reserve space for the response. For splitting long text, try our Text Chunk Splitter.

GPT token limits explained

GPT token limits differ by model. GPT-4 Turbo supports up to 128K tokens in a single context window. GPT-4 (standard) typically offers 8K or 32K depending on the variant. GPT-3.5 Turbo has a 16K context. Claude models often support 100K or 200K tokens. Use this AI token counter to see how your prompt fits each model and to compare GPT-4 vs GPT-3.5 vs Claude context sizes before you send.

How to avoid token limit errors

• Check your prompt size with a GPT token calculator or ChatGPT token calculator before sending. Reserve part of the context for the response using the slider above.
• Trim long instructions or paste only the relevant excerpt. Use our Prompt Formatter to clean and structure text first.
• For very long documents, split content with our Text Chunk Splitter and send in chunks, or summarize sections before feeding into the model.
• If you hit the limit, switch to a model with a larger context (e.g. GPT-4 Turbo 128K) or reduce input and reserved output.

Token cost optimization tips

Our token cost estimator shows an approximate input cost per model. Cost is based on typical list prices per 1,000 input tokens—output tokens and actual provider pricing may differ. To optimize: (1) keep prompts concise and well-structured with our Prompt Formatter; (2) use a smaller or cheaper model when the task doesn’t need the largest context; (3) reserve only the output space you need so you don’t over-count. This tool gives you a quick estimate; always check the provider’s latest pricing for exact costs.

GPT-4 Token Limit Calculator (128K Context Explained)

GPT-4 Turbo supports a 128K token context window—roughly 96,000 words or hundreds of pages of text in a single request. A GPT-4 token limit calculator helps you see how much of that window your prompt and reserved response will use. Token counting matters because the model must fit both your input and its reply within the limit; going over causes errors or cut-off responses. Use the tool above to estimate your prompt size and compare it against the 128K context so you can plan long documents, multi-turn conversations, or large inputs with confidence.

ChatGPT Token Calculator for API Users

If you use the ChatGPT API or other LLM APIs, a token calculator is essential for token budgeting and cost control. Plan your context window by reserving a percentage of tokens for the model's response (the slider above does this), then keep your input within the remaining space. That way you avoid overflows and unnecessary retries. For cost control, use the estimated input and total cost as a ballpark—then trim prompts or switch models when the numbers add up. This ChatGPT token calculator gives you quick, client-side estimates so you can iterate on prompts and context window planning without calling the API first.