Tool4SaaS

AI Detector

Check if text was written by AI. Analyze sentence variance and burstiness to estimate the likelihood of AI generation.

Enter text above for heuristic analysis

Heuristic: burstiness = std dev of sentence lengths; variance = mean squared deviation of sentence lengths; repetition score = 1 − (unique words / total words); perplexity proxy via uncommon word ratio (words outside top-100 common list). Weighted likelihood ≈ 0.3×burstiness + 0.2×variance + 0.2×repetition + 0.3×perplexity; short texts pulled toward 50% (uncertain).

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About the author

Written and maintained by the Tool4SaaS team. Every tool runs locally in your browser and is tested in-house for accuracy. Last updated: .

Frequently asked questions

Heuristic only ~70% — checks burstiness, variance and uncommon words. Not for academic decisions.

Yes, burstiness and variance scoring run locally; your draft is never sent for analysis.

Yes, it is free, works offline in your browser, and your data never leaves your device.

How to use AI Detector

  1. Paste text: Paste text to check.
  2. View score: See AI likelihood % with bar.
  3. Interpret: High burstiness and low variance suggest AI.