B
GPTZero
B Tier · 7.5/10
Leading AI content detector used by educators and publishers to identify AI-generated text
Last updated: 2026-04-02Free tier available
Score Breakdown
9.0
Ease of Use7.0
Output Quality7.0
Value7.0
FeaturesThe Good and the Bad
What we like
- +Most accurate AI detector in independent benchmarks -- consistently beats Originality.ai and others
- +Sentence-level highlighting shows exactly which parts triggered the detection, not just a score
- +Dead simple interface -- paste text, get a result in seconds
- +Free tier is generous enough for occasional checks without paying
What could be better
- −False positives are still a real problem -- human-written text gets flagged as AI more often than you'd expect
- −Accuracy drops noticeably on heavily edited or paraphrased AI text
- −No detection tool can reliably catch AI content that's been rewritten by a human, which limits usefulness
- −Plagiarism checker is only on Premium and doesn't match Turnitin's depth
Pricing
Free
$0
- ✓5,000 words/month
- ✓Single document scan
- ✓Basic AI detection
- ✓Sentence-level highlighting
Essential
$10/month
- ✓150,000 words/month
- ✓Batch file uploads
- ✓Detailed writing reports
- ✓API access
Premium
$16/month
- ✓300,000 words/month
- ✓Batch file uploads
- ✓Full writing reports
- ✓Plagiarism detection
- ✓API access
- ✓Priority support
Known Issues
- Non-native English speakers' writing gets flagged as AI-generated at higher rates, raising fairness concernsSource: Reddit r/professors · 2026-03
- Detection accuracy drops significantly on content generated by Claude and GPT-4o with custom instructionsSource: Reddit r/ChatGPT · 2026-02
- Batch upload feature occasionally fails silently on large PDF filesSource: G2 Reviews · 2026-01
Best for
Educators who want a quick check on student submissions, and publishers who need a first-pass AI content screen.
Not for
Anyone who expects 100% accuracy. No AI detector is reliable enough to be the sole basis for an accusation of cheating.
Our Verdict
GPTZero is the best AI detector available right now, but that's a low bar. It's more accurate than competitors and the sentence-level highlighting is genuinely useful. But false positives remain a serious issue, especially for non-native English writers. Use it as one signal among many, not as definitive proof. The fundamental problem is that AI detection is an arms race, and detectors are losing.
Sources
- GPTZero official site (accessed 2026-04-02)
- Reddit r/professors (accessed 2026-04-02)
- G2 Reviews (accessed 2026-04-02)
- Independent accuracy benchmarks (accessed 2026-04-02)