AI Detection Benchmark
Systems label private pre-2022 human documents and AI rewrites of them as human or AI written. Both LLMs and commercial detectors are scored by balanced accuracy.
Published September 30th, 2026. The board compares models with GPTZero, Pangram and other detectors on balanced accuracy.
- Made by
- Vals AI
- Released
- September 2026
- Kind
- Taste and style
- Level
- Expert
- Scored
- Checked automatically
- Answers
- Multiple choice
- Tasks
- Kept private
- Strongest model tested
- GPT-6 Astra #3 on the capability index
- Last model added
- September 2026
- Scores refreshed
- November 12th, 2026
Claude Opus 5.5 leads with 98.4% among models released by September 2026
Best score per entry from the benchmark's own leaderboard, read on November 12th, 2026. Where a model ran with several settings or harnesses, we keep its best. Names in gray aren't in our model list: fine-tunes, agent systems, products and older models. They don't count toward leaders.
The newest model with a score here came out in September 2026, and nobody has tested a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:
- Claude Fable 5.2
-
Gemini 4 Carbon - GPT-6.1 Sol
- GPT-6.1 Terra
- and 14 more
- 1 Claude Opus 5.5 98.4%
- 2 GPT-6 Astra 95.8%
- 3 detector/originality 94.1%
- 4 detector/pangram 93.9%
- 5 detector/gptzero 78.1%
- 6 detector/sapling 77.5%
- 7
DeepSeek V4.1 Flash 65.4% - 8 detector/copyleaks 64.6%
Source: Official AI Detection Benchmark leaderboard
| # | Entry | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | Claude Opus 5.5 | 98.4% | Sep 2026 | Official leaderboard | |
| 2 | GPT-6 Astra | 95.8% | Sep 2026 | Official leaderboard | |
| 3 | detector/originality | 94.1% | Official leaderboard | ||
| 4 | detector/pangram | 93.9% | Official leaderboard | ||
| 5 | detector/gptzero | 78.1% | Official leaderboard | ||
| 6 | detector/sapling | 77.5% | Official leaderboard | ||
| 7 | DeepSeek V4.1 Flash | 65.4% | Sep 2026 | Official leaderboard | |
| 8 | detector/copyleaks | 64.6% | Official leaderboard |
2 models have held number one on the official leaderboard since its release in September 2026
Lab claims count from the day the card came out, independent runs from the model’s release.
Source: Official AI Detection Benchmark leaderboard
GPT-6 Astra on the official leaderboard passed 85% in September 2026
All the scores we have, one dot each, so a model tested at several settings appears more than once.
Source: Official AI Detection Benchmark leaderboard
No lab model card reports it yet
We read the headline results of 522 launch posts from 52 labs, and none of them list this benchmark.
More in Writing and taste
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- WritingBench Fading Models complete 1,000 real-world writing requests across 6 domains and 100 subdomains. A judge model scores each reply on five query-specific criteria. GPT-5 83.9
- Creative Writing (MiniMax in-house) Only in system cards Models write creative pieces for real Hailuo AI user requests. Automatic assessments score the writing.
MiniMax-Text-01 81.3% - DeepSeek Chinese functional writing evaluation Only in system cards Models answer 3,170 everyday Chinese writing prompts such as reports, emails and speeches. Pairwise judging against a baseline model gives a win rate. DeepSeek-V4-Pro 62.6%
- Slide generation human evaluation (Z.ai) Only in system cards People compare HTML slide decks from two models on content, layout and visual quality. Metric is overall win rate. GLM-5 67.5%
- Task-dependent output homogenization evaluation Only in system cards Models answer prompts several times. A judge scores functional diversity where it is wanted and consistency where one answer is right.
Muse Spark 0.21