Best AI Humanizer of 2026 (October Edition)
In HumanizerEval's October 2026 review, run October 22, 2026, StealthGPT was the best AI humanizer of 11, with an 80.3% mean strict-bypass rate across six detectors on the same 50 English texts. Undetectable.ai followed at 71.3% and WriteHuman at 69.7%. HumanizerEval is a humanizer benchmark created and run by the StealthGPT team.
Last updated November 2026. The ranking below is from HumanizerEval's October 2026 review, run October 22, 2026 (America/New_York).
StealthGPT is an AI humanizer for essays, papers, and everyday writing, with Super, Standard, and Lite models. HumanizerEval is a public AI humanizer benchmark operated by the StealthGPT team. It scores every output through external detector APIs and publishes the per-sample data. This article reports that October cycle. It is not a promise that any tool will pass a given detector, and Turnitin was not in the panel.
What is the best AI humanizer in 2026?
StealthGPT is the best AI humanizer in this October 2026 edition. It earned the highest average strict-bypass rate, 80.3%, of the 11 tools HumanizerEval tested in its October 2026 review, on 50 texts and six detectors. Undetectable.ai placed second at 71.3% and WriteHuman third at 69.7%. StealthGPT was also the only tool to pass all six detectors on more than one text, doing so on 17 of 50. The tested StealthGPT setting was Super, in quality mode, through the API.
On Pangram, StealthGPT's strict-bypass rate (88%) exceeded that of the next-best humanizer (40%) by 48.0 points. HumanizerEval defines a "strict bypass" as receiving a human score above 50%, regardless of the vendor's label. Because HumanizerEval only tested 50 texts per humanizer, it estimates the 95% confidence interval on each humanizer's true strict-bypass rate to be roughly plus or minus 14 points. Differences of just a few points therefore should not be read as meaningful, though larger differences, such as StealthGPT's 48.0 point lead over the next-best humanizer on Pangram, sit outside that confidence band.
The ranked table below is from the October 22, 2026 cycle and uses the same 50 English texts. StealthGPT also had the highest share of texts that cleared all six strict-bypass thresholds: 17 of 50. In this table, each detector column shows the strict-bypass rate: the share of the 50 texts assigned a human score above 50% by that detector. "Cleared all 6" is the number of texts that cleared every detector's strict-bypass threshold. Source: HumanizerEval, October 2026 review.
| Rank | AI humanizer | Mean bypass | Pangram | GPTZero | Originality.ai Turbo | Originality.ai 5.0 | ZeroGPT | Winston AI | Cleared all 6 |
|---|---|---|---|---|---|---|---|---|---|
| 1 | StealthGPT | 80.3% | 88% | 92% | 92% | 34% | 84% | 92% | 17/50 |
| 2 | Undetectable.ai | 71.3% | 40% | 86% | 98% | 4% | 100% | 100% | 1/50 |
| 3 | WriteHuman | 69.7% | 26% | 90% | 100% | 6% | 96% | 100% | 0/50 |
| 4 | Rephrasy | 62.3% | 26% | 70% | 86% | 0% | 92% | 100% | 0/50 |
| 5 | Grubby | 62.3% | 10% | 68% | 100% | 0% | 96% | 100% | 0/50 |
| 6 | RewriteAI | 56.3% | 2% | 54% | 98% | 0% | 90% | 94% | 0/50 |
| 7 | Phrasly | 48.7% | 4% | 44% | 72% | 0% | 82% | 90% | 0/50 |
| 8 | HIX Bypass | 44.0% | 0% | 6% | 66% | 0% | 92% | 100% | 0/50 |
| 9 | Humbot | 44.0% | 0% | 0% | 76% | 0% | 88% | 100% | 0/50 |
| 10 | BypassGPT | 41.3% | 0% | 4% | 56% | 0% | 88% | 100% | 0/50 |
| 11 | Ryne | 0.7% | 0% | 0% | 0% | 0% | 4% | 0% | 0/50 |
| Source text (no humanizer) | 0.3% | 0% | 0% | 0% | 0% | 2% | 0% |
HumanizerEval October 22, 2026 cycle, 50 texts. StealthGPT Super, quality mode, API. HumanizerEval is operated by StealthGPT.
The October 2026 edition of HumanizerEval's benchmark included Pangram 4.1, GPTZero 2026-10-07-base, Originality.ai Turbo, Originality.ai (model-5.0), ZeroGPT (default), and Winston AI 5.0. (In practice, this tiebreaker rule did not affect the relative rankings of any humanizers: Rephrasy and Grubby had identical mean bypass rates and all-six counts, as did HIX Bypass and Humbot, and all four of these humanizers had a "Cleared all 6" percentage of 0%. HumanizerEval lists Rephrasy fourth and HIX Bypass eighth, which is the published order on the October 2026 archive.)
The first-place setup HumanizerEval tested was Super, in quality mode, through the API, and can be tried by opening StealthGPT's AI Humanizer and selecting Super. It can also be found on the best AI humanizers comparison page.
How did HumanizerEval test these AI humanizers?
HumanizerEval, which is run by the StealthGPT team, tested every humanizer on the same 50 English texts, sent every output to the same six detector APIs, and ranked tools by mean strict-bypass rate. Where two humanizers have identical mean strict-bypass rates, HumanizerEval ranks the one with the higher "Cleared all 6" percentage higher. HumanizerEval's October 2026 evaluation tested each humanizer on the same set of 50 LLM-generated texts (364 to 997 words each; mean length 669 words). For each humanizer/detector pair, HumanizerEval computed the strict-bypass rate: the share of the 50 texts that received a human score above 50% after humanization with the given humanizer, and ranked the humanizers by their average strict-bypass rate across detectors. The review used methodology v1.0, ran on October 22, 2026, and is archived as report 2026-10-22-humanizer-comparison. See HumanizerEval methodology for the whole ruleset.
Ten of the texts were generated with each of five different LLMs: GPT-6.1 Sol, Claude Sonnet 5.5, Gemini 4 Argon, Grok 4.7, and DeepSeek V4.1 Flash. (The source texts are published. The humanized outputs are not.)
For each humanizer, HumanizerEval used what it describes as the most powerful configuration available on the cheapest paid plan. These results therefore describe paid configurations, not free plans. The recorded October 2026 settings were:
StealthGPT: Super, quality mode, API
Undetectable.ai: University / General Writing / More Human, v11sr
WriteHuman: API default
Rephrasy: v4
Grubby: Academic
RewriteAI: API default, in passages of up to 280 words (RewriteAI's API has a 300-word limit)
Phrasly: Standard model, API default (Phrasly Ultra was not enabled on HumanizerEval's Phrasly account)
HIX Bypass: Latest
Humbot: Advanced
BypassGPT: Enhanced
Ryne: Aggressive, beast mode
Limits of this test, stated plainly:
HumanizerEval ranks tools by detector scores, while quality is scored separately and does not enter the leaderboard. Because HumanizerEval is produced by the team behind one of the humanizers it evaluates (StealthGPT), it is worth keeping in mind that HumanizerEval's designers made all methodological decisions (which humanizers and detector models to test, which settings to use for each humanizer, which texts to test on, how to handle ties, etc.). SHA-256 of scores.csv,
fa08bce7ac679b6c067c2cbc39948e82940e6834a3c396562aae6d480037debc, is published on the October archive. Note that detector scores are obtained from APIs provided by the different vendors.Turnitin and Copyleaks were not included; in particular, Turnitin does not offer public API access that could support evaluations at this scale.
(For Originality.ai 5.0 in particular, the "AI-written %" metric does not purport to measure confidence the way the other detectors' metrics do, so Originality.ai 5.0's results should not be directly compared with those of Originality.ai Turbo.)
(HumanizerEval does separately assess humanizers' impact on factual consistency, writing quality/fluency, grammar and syntax, and preservation of stance/opinion, but these metrics do not factor into HumanizerEval's leaderboard.)
A 50-text sample is large enough to show wide gaps and too small to treat a few points as a decisive lead.
Anyone can recompute the aggregates from the public CSV by cloning the HumanizerEval data repo and running python3 scripts/verify_report.py reports/2026-10-22-humanizer-comparison.
How did each AI humanizer perform in October 2026?
In HumanizerEval's October 2026 review, StealthGPT led the mean bypass rate and the all-six count, other tools led or tied some of the easier detectors, and Ryne had the lowest bypass rate and the highest quality score. HumanizerEval tested StealthGPT, Undetectable.ai, WriteHuman, Rephrasy, Grubby, RewriteAI, Phrasly, HIX Bypass, Humbot, BypassGPT, and Ryne in that cycle. These notes pertain only to that evaluation. This article does not assess these AI text humanizers' features or pricing.
1. StealthGPT: 80.3% mean bypass, 17 of 50 cleared all six detectors
StealthGPT had the highest average strict-bypass rate (80.3%) of the 11 AI text humanizers we tested in October 2026. Of the 50 texts we humanized, StealthGPT's outputs passed all six of our AI detectors in 17 cases. Its best single-detector results were against Originality.ai Turbo (92%), GPTZero (92%), and Winston AI (92%). StealthGPT's humanized outputs preserved the quality of our source texts better than any tool we tested except Ryne, earning an 83.5% pass rate across our four quality dimensions. On average, StealthGPT made our texts 18% longer (length ratio of 1.18). The rest of the leaderboard, in descending order: StealthGPT's humanized texts passed all six of our AI detectors in 17 of 50 cases, more than any other tool we tested. Overall, StealthGPT earned the highest average strict-bypass rate (80.3%). It also posted the highest pass rates against Pangram (88%; 44 of 50 texts), GPTZero (92%; 46 of 50), and Originality.ai 5.0 (34%; 17 of 50). StealthGPT's humanized texts preserved quality well, earning an 83.5% pass rate across our four quality dimensions, which was second-highest among the tools we tested. Turnitin is not assessed using this panel. The live AI Humanizer product page, last updated November 7, 2026, also quotes this 80.3% October figure.
2. Undetectable.ai: 71.3% mean bypass, 1 of 50 cleared all six
Undetectable.ai (71.3%) and WriteHuman (69.7%) came in second and third, respectively. Undetectable.ai's humanized texts passed all six of our AI detectors in one case. Undetectable.ai posted the second-highest average strict-bypass rate (71.3%). Its humanized texts passed all six of our AI detectors in one case, making it the only tool besides StealthGPT to achieve this feat. It earned perfect pass rates against Winston AI and ZeroGPT and posted a near-perfect pass rate against Originality.ai Turbo (98%), but it passed Pangram on 40% of texts and Originality.ai 5.0 on 4%. Undetectable.ai made our texts longer than any other tool we tested (length ratio of 1.27). Its humanized texts preserved quality less well than StealthGPT's, earning a 52.5% pass rate across our quality metrics.
3. WriteHuman: 69.7% mean bypass, 0 of 50 cleared all six
WriteHuman's outputs did not pass all six detectors in any case, but they underwent the least change of length of the tools that managed an average bypass rate of over 1% (length ratio of 1.06). WriteHuman posted the third-highest average strict-bypass rate (69.7%). Its humanized texts did not pass all six of our AI detectors in any case, but it still managed respectable results, including perfect pass rates against Winston AI and Originality.ai Turbo, 96% against ZeroGPT, and 90% against GPTZero. Of the tools that managed an average bypass rate of over 1%, WriteHuman changed our texts' lengths the least (length ratio of 1.06). Its pass rates against factual consistency (38%) and stance preservation (50%) dragged down its overall quality score.
4. Rephrasy: 62.3% mean bypass
Its humanized texts preserved quality less well than StealthGPT's outputs, earning a 59.0% pass rate across our quality metrics. Rephrasy ranked fourth at 62.3%, tied with Grubby on the mean, and cleared all six detectors on 0 of 50 texts. Rephrasy earned a perfect pass rate against Winston AI and respectable results against Originality.ai Turbo (86%) and Pangram (26%).
5. Grubby: 62.3% mean bypass
Grubby ranked fifth at the same 62.3% mean and also cleared all six detectors on 0 of 50 texts. Grubby earned a perfect pass rate against Winston AI and Originality.ai Turbo (tying WriteHuman), but it fared less well against Pangram (10%; 5 of 50 texts) and Originality.ai 5.0 (0%). Its humanized texts preserved quality better than most of the tools we tested (79.5% pass rate across our quality metrics), including the highest pass rate against factual consistency (76%).
6. RewriteAI: 56.3% mean bypass
RewriteAI ranked sixth at 56.3% and cleared all six detectors on 0 of 50 texts. RewriteAI earned near- or perfect pass rates against Originality.ai Turbo (98%) and Winston AI (94%), but it fared less well against Pangram (2%; 1 of 50 texts) and Originality.ai 5.0 (0%). Note: RewriteAI's API has a 300-word limit, so we tested it using passages of up to 280 words.
7. Phrasly: 48.7% mean bypass
Phrasly ranked seventh at 48.7% on its Standard model, and it cleared all six detectors on 0 of 50 texts. Phrasly fared especially poorly against Originality.ai 5.0 (0%) and Pangram (4%). Its humanized texts preserved quality better than most of the tools we tested (75.5% pass rate across our quality metrics). Note: Phrasly Ultra was not turned on in the Phrasly account we used for testing, so our results do not apply to this model.
8. HIX Bypass: 44.0% mean bypass
HIX Bypass ranked eighth at 44.0% and cleared all six detectors on 0 of 50 texts. It earned a perfect pass rate against Winston AI and a respectable one against ZeroGPT (92%), but it fared poorly against Originality.ai 5.0 and Pangram (0% against both) and GPTZero (6%). Naturalness passed on 6% of outputs. Mean quality was 48.0%.
9. Humbot: 44.0% mean bypass
Its humanized texts preserved quality less well than most of the tools we tested (52.0% pass rate across our quality metrics), including just a 6% pass rate against naturalness. Humbot ranked ninth at the same 44.0% mean and cleared all six detectors on 0 of 50 texts. It was perfect on Winston AI, but it passed GPTZero, Pangram, and Originality.ai 5.0 on none of the 50 texts.
10. BypassGPT: 41.3% mean bypass
BypassGPT ranked tenth at 41.3% and cleared all six detectors on 0 of 50 texts. It earned a perfect pass rate against Winston AI but fared poorly against Originality.ai 5.0 and Pangram (0% against both) and GPTZero (4%). Its humanized texts preserved quality less well than any of the other tools we tested (47.5% pass rate across our quality metrics), and none passed our naturalness metric.
11. Ryne: 0.7% mean bypass, highest quality score
Ryne ranked last on bypass, at 0.7%, after passing ZeroGPT on 2 of 50 texts and passing none of the other five detectors on any text. Overall, it managed the lowest average strict-bypass rate (0.7%). That said, Ryne's humanized texts preserved quality better than any other tool we tested (87.5% pass rate across our quality metrics), including strong results against stance preservation (94%) and naturalness (92%). Ryne also changed our texts' lengths the least of any of the tools we tested (length ratio of 1.02). The untouched source texts, scored with no humanizer applied, had a 0.3% mean bypass rate.
Which AI humanizer is best for which job?
The best tool depends on which detector and which tradeoff you care about, because the October 2026 panel shows wide disagreement across detectors, and quality is not part of the official rank. These matches use only that cycle's results.
Best overall in this review: StealthGPT tops in terms of the mean bypass rate with 80.3% (with 17 out of 50 outputs clearing all six detectors).
Best on Pangram and GPTZero: StealthGPT is rated 88% (44/50) by Pangram 4.1 and 92% (46/50) by GPTZero. HumanizerEval reports Pangram as the detector that most clearly separated the field; the average tool passed it on 18% of the same texts.
Best on the hardest detector in the panel: StealthGPT on Originality.ai 5.0, at 34% strict bypass (17 of 50). The average tool passed that detector on 4% of texts. Eight of the 11 tools passed it on zero texts.
Best on ZeroGPT: Undetectable.ai, scored 100% (50/50). Eight tools still scored higher than StealthGPT's 84% on this detector.
Best on Originality.ai Turbo: Grubby and WriteHuman, both 100% (50 of 50). StealthGPT scored 92%.
Best on Winston AI: 7 of the tools (Undetectable.ai, WriteHuman, Rephrasy, Grubby, HIX Bypass, Humbot, and BypassGPT) scored 100%. StealthGPT scored 92%. Winston AI was the easiest detector in the panel; the average tool passed it on 89% of texts.
Best quality score, reported separately: Ryne had the highest mean quality (87.5%), followed by StealthGPT (83.5%) and Grubby (79.5%).
For an academic genre taken from the same October texts, see StealthGPT results, calculated November 7, 2026, for 29 pieces of student writing at student AI humanizer study. Those 29-text figures are a subset of, and do not supersede, StealthGPT's 50-text leaderboard position above. For free-plan limits rather than these paid-tier benchmark settings, see the 2026 free AI humanizer comparison and what's the best free AI humanizer in 2026.
What do the quality scores show?
Quality scores in HumanizerEval's October 2026 review are reported separately from rank: Ryne was highest at 87.5%, StealthGPT achieved the second-highest mean quality pass rate of the AI humanizers tested at 83.5%, and BypassGPT was last at 47.5%. A pass means HumanizerEval found no issue in that dimension on the delivered output. These rates never enter the leaderboard, so a weighting choice cannot change the order.
| AI humanizer | Mean quality | Factual consistency | Naturalness | Syntax integrity | Stance preservation |
|---|---|---|---|---|---|
| Ryne | 87.5% | 64% | 92% | 100% | 94% |
| StealthGPT | 83.5% | 68% | 82% | 98% | 86% |
| Grubby | 79.5% | 76% | 64% | 100% | 78% |
| Phrasly | 75.5% | 50% | 70% | 98% | 84% |
| RewriteAI | 67.5% | 40% | 52% | 100% | 78% |
| WriteHuman | 59.0% | 38% | 50% | 98% | 50% |
| Rephrasy | 59.0% | 32% | 44% | 98% | 62% |
| Undetectable.ai | 52.5% | 32% | 28% | 90% | 60% |
| Humbot | 52.0% | 30% | 6% | 100% | 72% |
| HIX Bypass | 48.0% | 22% | 6% | 98% | 66% |
| BypassGPT | 47.5% | 24% | 0% | 100% | 66% |
Quality scores from the October 22, 2026 cycle, 50 texts. These rates do not enter the leaderboard.
Source: HumanizerEval, October 2026 review, same 50 English texts. Quality is reported separately from rank.
Syntax integrity was high for almost every tool. The larger gaps were in factual consistency and naturalness. That is why a mean bypass rate and a quality table answer different questions: a tool can score well on easier detectors and still change meaning or read poorly, and a tool can preserve the draft and still fail the harder detectors.
Frequently asked questions
What is an AI humanizer?
An AI humanizer rewrites AI-generated or AI-assisted text so the wording and sentence structure read more like a person wrote them, and so AI-content detectors are less likely to flag the result. StealthGPT does that with dedicated Super, Standard, and Lite models, plus document tools and an AI detector in the same workspace.
What is StealthGPT?
StealthGPT is an AI humanizer, a service that uses AI to rewrite AI-generated (or AI-assisted) text to make it sound more human-written, and less likely to be labeled as AI by AI content detectors. It offers Super, Standard, and Lite models, a built-in AI detector, document upload, and an API. In HumanizerEval's October 2026 review, its tested setting was Super, quality mode, through the API, and that configuration ranked first of 11 tools at 80.3% mean strict bypass.
Who runs HumanizerEval, and should I trust the results?
HumanizerEval is an evaluation service for AI humanizers, run by the StealthGPT team. It is important to note that HumanizerEval is run by the StealthGPT team, so although its reviews are archived and cannot be retrospectively tampered with, they are not totally impartial. The detector scores come from vendor APIs, every tool received the same 50 texts, the settings are published, and the per-sample scores can be recomputed from a public CSV on the October 2026 review archive. A first-party benchmark can still be checked; it should not be described as an independent lab.
What is the best AI humanizer for GPTZero or Pangram?
In the October 2026 review, StealthGPT had the best strict-bypass rate on both: 92% on GPTZero (46 of 50 texts) and 88% on Pangram 4.1 (44 of 50 texts). GPTZero was much easier for the field as a whole (the average tool passed it on 47% of texts) than Pangram (18%). The next-best Pangram rate was Undetectable.ai at 40%.
Can an AI humanizer bypass Turnitin?
This October 2026 benchmark does not answer that question, because Turnitin was not in the detector panel. HumanizerEval says Turnitin has no public API for testing at 50 samples per tool. The StealthGPT AI Humanizer page also states that the October panel does not measure Turnitin. Do not treat the six-detector rates above as Turnitin results.
Is the best free AI humanizer the same as the best overall?
Not necessarily. HumanizerEval says it tests each AI humanizer using the strongest configuration/model the service touts, and accesses each AI humanizer using its cheapest paid plan/tier, so the 80.3% figure describes StealthGPT Super on a paid API configuration, not a free demo. StealthGPT's live product page, updated November 7, 2026, says the desktop demo accepts up to 100 words. For a comparison of documented free offers, use the free AI humanizer guide.
How often is this ranking updated?
This article is the October 2026 edition and is based on HumanizerEval's October 2026 review, conducted on October 22, 2026, and published as an immutable archive.
