Best for GPTZero
Humanizers ranked by their measured bypass rate against GPTZero.
One of the earliest AI text detectors, widely used by educators to check whether student writing was generated with AI.
| Rank Position by GPTZero bypass rate on this cycle. Learn more → | Humanizer | GPTZero Bypass Fraction of samples GPTZero classified as human-written. Learn more → ↓ | Overall Overall score across all detectors, after penalties. Learn more → | Penalties Total points deducted from the overall score when output-quality issues were detected. Hover a row's chip to see why. Learn more → | Last Tested |
|---|---|---|---|---|---|
| 1 | Undetectable.ai undetectable.ai | 94.1 | 72.17 | −10.0Penalties applied
| 1d ago |
| 2 | Walter Writes walterwrites.ai | 82.5 | 62.84 | −8.0×2Penalties applied
| 1d ago |
| 3 | StealthGPT stealthgpt.ai | 80.5 | 61.52 | −10.0×3Penalties applied
| 1d ago |
| 4 | Phrasly phrasly.ai | 76.8 | 61.47 | −8.0×3Penalties applied
| 1d ago |
| 5 | AI Humanize io aihumanize.io | 65.8 | 59.66 | −10.0×2Penalties applied
| 1d ago |
| 6 | WriteHuman writehuman.ai | 60.8 | 73.07 | −1.0Penalties applied
| 1d ago |
| 7 | Humanize AI Pro www.humanizeai.pro | 58.7 | 70.49 | None | 1d ago |
| 8 | Stealth Writer stealthwriter.ai | 36.5 | 68.07 | −3.0×2Penalties applied
| 1d ago |
| 9 | Super Humanizer superhumanizer.ai | 34.0 | 54.13 | −5.0×3Penalties applied
| 1d ago |
| 10 | HIX Bypass bypass.hix.ai | 21.9 | 64.84 | None | 1d ago |
| 11 | Humbot humbot.ai | 12.1 | 66.42 | −1.0Penalties applied
| 1d ago |
| 12 | Grammarly www.grammarly.com/ai-humanizer | 0.0 | 53.38 | None | 1d ago |
| 13 | NoteGPT notegpt.io/ai-humanizer | 0.0 | 44.04 | None | 1d ago |
Higher bypass rate alone ≠ a better tool. See the balanced overall ranking on the main leaderboard .
How scores are computed
See the full methodology →Overall score formula
- Bypass 42% Share of detector tests where the output was classified as human.
- Meaning 32% How well the output preserves the original meaning.
- Readability 16% How clear, fluent, and natural the writing reads, rated by a language model.
- Consistency 10% How evenly the humanizer performs across writing categories.
Penalties (right) are deducted from the overall score. Final score is clamped at 0.
Possible penalties
| Code | Penalty | Max |
|---|---|---|
| Identical to input The tool returned the input mostly unchanged. No real humanization happened. | −2.0 | −10.0 |
| Refusal The tool refused to humanize the input, often due to a content-policy block. | −1.0 | −10.0 |
| Meaning drift The output's meaning drifted significantly from the original input. | −1.0 | −10.0 |
| Length inflation The output ran much longer than the input, a common trick that pads text to dilute the AI signal. | −1.0 | −10.0 |
| Length deflation The output came back much shorter than the input. The rewrite dropped content instead of paraphrasing it. | −1.0 | −10.0 |
Maximum possible total penalty: −50.0 (off 100).
Top 3 for GPTZero
- Undetectable.ai 94.1%
- Walter Writes 82.5%
- StealthGPT 80.5%
Frequently Asked Questions
Which AI humanizer best bypasses GPTZero?
The top of the ranking on this page is the humanizer with the highest measured bypass rate against GPTZero in the latest cycle. Bypass rate is the share of test samples GPTZero classified as human-written after humanization. We re-run this every cycle, so the leader can change month to month — and a tool that tops GPTZero is not necessarily best overall.
How is the GPTZero bypass rate measured?
Every humanizer processes the same fixed prompt set, and each output is submitted to GPTZero. We record the raw verdict for every sample and report the fraction marked human as a 0–100 score. The raw per-sample verdicts are published per cycle in detector-scores.json, so anyone can recompute the number.
Does a high GPTZero score mean a humanizer is good?
Not on its own. A single detector's bypass rate ignores meaning preservation, readability, and how a tool performs against the other detectors. Use this page to compare GPTZero specifically, then check the overall leaderboard for the balanced ranking before deciding.