HumanizerEval

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September 2026 review · same 50 texts

Rephrasy vs RewriteAI

In the September 2026 HumanizerEval review, Rephrasy and RewriteAI rewrote the same 50 English texts. Rephrasy cleared all 5 detectors on 20 of them; RewriteAI on 13. The difference is mostly Pangram: on 13 samples Rephrasy passed it where RewriteAI failed, and the reverse happened on 4. On GPTZero, Originality.ai and Winston AI the two were close to even.

Per-sample agreement

Per-sample agreement, September 2026. Counts are out of the 50 shared samples, computed at the 50% human-score threshold. Margin counts the samples only one tool passed, higher count first.
DetectorPassed more oftenMarginBoth passedNeither passed
Pangram 4.0Rephrasy13 to 41023
GPTZero 2026-09-13-baseRephrasy5 to 4392
Originality.ai turboRewriteAI7 to 6370
ZeroGPT defaultRephrasy6 to 0440
Winston AI 5.0Rephrasy2 to 0480
All 5 detectorsRephrasy11 to 4926

Every count is computed from scores.csv at build time, not transcribed. “Neither passed” counts the texts that defeated both tools; on Pangram that was 23 of 50 here.

Quality and output discipline

Quality and output discipline, September 2026.
MeasureRephrasyRewriteAI
36%54%
30%40%
92%100%
60%94%
1.131.09
32
00
v4API default, passages of up to 280 words (300-word API limit)
Websiterephrasy.ai rewriteai.com

On per-sample quality scores, Rephrasy scored higher on 9 samples, RewriteAI on 25, and the two tied on 16. RewriteAI’s output was shorter on 27 of 50 samples; mean length ratios were 1.13 and 1.09, or 13% longer than the input and 9% longer than the input respectively.

Where each one outperforms the other

Rephrasy

  • Pangram: passed 23 of 50 against 14, including 13 samples where RewriteAI failed, against 4 the other way.
  • GPTZero: passed 44 of 50 against 43, including 5 samples where RewriteAI failed, against 4 the other way.
  • Originality.ai: passed 6 samples where RewriteAI failed, even though it was detected more often overall, passing 43 to 44.
  • ZeroGPT: passed 50 of 50 against 44, including 6 samples where RewriteAI failed, against 0 the other way.
  • Winston AI: passed 50 of 50 against 48, including 2 samples where RewriteAI failed, against 0 the other way.

RewriteAI

  • Pangram: passed 4 samples where Rephrasy failed, even though it was detected more often overall, passing 14 to 23.
  • GPTZero: passed 4 samples where Rephrasy failed, even though it was detected more often overall, passing 43 to 44.
  • Originality.ai: passed 44 of 50 against 43, including 7 samples where Rephrasy failed, against 6 the other way.
  • Factual consistency: 54% against 36%.
  • Naturalness: 40% against 30%.
  • Syntax integrity: 100% against 92%.
  • Stance preservation: 94% against 60%.
  • Length: shorter output on 27 of 50 samples, which matters under a word limit.

Rephrasy vs RewriteAI FAQ

Is Rephrasy better than RewriteAI?

In the September 2026 HumanizerEval review, Rephrasy cleared all 5 detectors on 20 of the 50 shared samples and RewriteAI on 13. On GPTZero, Originality.ai and Winston AI the two were within 6 points of each other. Quality ran 9 samples to 25, with 16 ties.

Which humanizer is best for Pangram, Rephrasy or RewriteAI?

Rephrasy. In September 2026, Rephrasy passed Pangram on 23 of the 50 shared samples and RewriteAI on 14. On 13 samples Rephrasy passed where RewriteAI failed; the reverse happened on 4. Both failed on 23.

Which humanizer changes the text less?

RewriteAI. It scored higher on per-sample quality on 25 of 50 samples, against 9. Rephrasy’s outputs averaged 1.13× the input length and passed factual consistency on 36%; RewriteAI’s averaged 1.09× and passed on 54%. On stance preservation the split was 60% to 94%. RewriteAI produced the shorter output on 27 of 50 samples.

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