AI Humanizer BenchmarkThe detector panel
Every humanized output is scored by these seven commercial AI detectors, each weighted equally, ordered here from hardest to easiest to beat this cycle. The bar is the mean human-likelihood the detector assigned across all 363 outputs: lower means stricter. Each detector page ranks all humanizers against that detector alone.
Copyleaks
Enterprise detection used by universities and businesses, where a flag can carry formal consequences.
Normalization: Reports AI probability; inverted (human = 1 - ai).
Current best performer: AI Humanize at 67% bypass.
Originality.ai
A paid detector used by publishers and SEO teams before content goes live; consistently the strictest scorer in our panel.
Normalization: Reports AI probability; inverted (human = 1 - ai).
Current best performer: UndetectedGPT at 79% bypass.
Winston AI
A commercial detector scoring documents for AI involvement, plagiarism, and readability.
Normalization: Reports a 0-100 human score; divided by 100.
Current best performer: WriteHuman at 82% bypass.
GPTZero
The detector most widely used in education, where much AI-checking of written work actually happens.
Normalization: Reports a 0-1 AI probability; inverted to human = 1 - ai.
Current best performer: CleverHumanizer at 90% bypass.
ZeroGPT
A free browser-based detector with very wide consumer reach.
Normalization: Reports AI percentage; inverted and divided by 100.
Current best performer: WriteHuman at 92% bypass.
QuillBot
A free detector inside the QuillBot writing suite, widely used by students.
Normalization: Reports AI percentage; inverted and divided by 100.
Current best performer: SmartHumanizer at 94% bypass.
Grammarly
AI detection integrated into Grammarly's writing assistant, applied where drafting happens.
Normalization: Reports AI percentage; inverted and divided by 100.
Current best performer: CleverHumanizer at 97% bypass.
Bypass rate is the fraction of samples a detector marks as human-written. For the full method, see how we measure bypass rate.