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AI & Prompt Tools · Free tool

AI Output Length Estimator

Predict how many tokens an LLM will generate for summaries, rewrites, code, or essays — budget your max_tokens.

Updated April 2026

Predict how many output tokens a prompt will likely produce so you can budget context window and cost.

Ratio
0.25x
Output tokens
250
~ Words
188
Summaries compress content to roughly a quarter of the input.

Rough averages across popular models. Always set a hardmax_tokenscap in production.

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What it does

Estimate how long an LLM response will be by task type — budget max_tokens without truncation.

Runs entirely in your browser — no upload, no account, no watermark. For more tools in this category see the full tools index.

How to use it

  1. Pick the task type.
  2. Enter input tokens.
  3. Read the output estimate.

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