AI Detector Tools Compared (2026)

ToolAccuracyFalse PositivesFree LimitPrice/moBest For
AI Detector86%7%UnlimitedFreeWord heatmap + rewrites
GPTZero89%6%5K chars$10Academics
ZeroGPT84%9%UnlimitedFreeGeneral use
Copyleaks88%4%Limited$11Business
Quillbot82%11%Limited$10Simplicity
Originality.ai87%7%None$15Agencies
Winston AI85%9%None$12Education
Sapling80%12%UnlimitedFreeShort texts
Content at Scale83%8%25K charsFreeLong articles

Accuracy figures based on our testing with 50 text samples (20 human, 20 GPT-4o, 10 Claude). Your results may vary.


Feature Comparison

Not all detectors are created equal. Here’s what separates them beyond raw accuracy:

FeatureAI DetectorGPTZeroZeroGPTCopyleaksOriginality.ai
Word-level heatmap
Sentence highlighting
Rewrite suggestions
No sign-up required
Unlimited free checks
API available
Batch processing
Plagiarism check

How We Test

We use a standardized test set of 50 texts:

Each tool is tested blind on the same inputs. We measure:

All texts are between 150-500 words. We test each tool 3 times per text and use the median score to reduce variance.


Key Takeaways

Best accuracy: GPTZero and Copyleaks lead in raw detection accuracy, but both require payment for meaningful use.

Best free option: AI Detector and ZeroGPT both offer unlimited free checks. AI Detector adds word-level heatmap and rewrite suggestions that ZeroGPT doesn’t have.

Best for agencies: Originality.ai offers batch processing and team features, but at the highest price point ($15/month with no free tier).

Best for students: If you’re checking your own writing to avoid false positives, AI Detector’s word-level highlighting is the most useful — you can see exactly what to change.


What Accuracy Actually Means

An “89% accuracy” claim sounds impressive. But what does it mean in practice?

The takeaway: no detector is reliable enough to use as definitive proof. Use them as screening tools, not verdict machines.

Read more: AI Detector Accuracy: The Full Picture


Full Reviews


Detailed Comparisons

Looking for a specific matchup? Read our in-depth comparisons:

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Detect by AI Model

Not sure which AI wrote the text? Check model-specific detection:


Best AI Detector by Use Case