Best AI Content Detectors
Originality.ai vs GPTZero vs Copyleaks vs Writer & more
AI Detector Comparison Table
| Rank | Tool | Best For | Accuracy | Pricing | Link |
|---|---|---|---|---|---|
| 1 | Originality.ai | SEO Teams & Agencies | 98.7% | $0.01/100 words | Try Originality.ai → |
| 2 | GPTZero | Educators & Students | 97.4% | Free–$10/mo | Try GPTZero → |
| 3 | Copyleaks | Enterprise & Universities | 99.1% | Custom pricing | Try Copyleaks → |
| 4 | Winston AI | Publishers & Long-Form | 98.9% | From $9.99/mo | Try Winston AI → |
| 5 | Writer.com | Quick Free Checks | 97.8% | Free | Try Writer → |
| 6 | Sapling | Developers & API | 96.5% | Free–$25/mo | Try Sapling → |
| 7 | Content at Scale | Long-Form SEO | 98.2% | Free | Try Content at Scale → |
| 8 | ZeroGPT | Fast & Free | 95.8% | Free | Try ZeroGPT → |
| 9 | Hugging Face | Open-Source | 99.3% | Free | View Models → |
| 10 | Quillbot | Students & Casual | 94.2% | Free | Try Quillbot → |
Which AI Detector Is Right for You?
Answer 2 quick questions → get your personalized #1 tool
🔬 My Testing Methodology
Duration: 30 days
What I Tested: Used 100+ real content pieces across different AI platforms to measure detection accuracy.
Evaluation Criteria: Accuracy rates, false positive rates, commercial licensing, and practical utility for different user types.
Top 10 AI Content Detectors — Detailed Reviews
1. Originality.ai — Best Overall & Most Accurate
98%+ accuracy, plagiarism + AI detection, used by 10,000+ agencies.
Industry-leading accuracy with comprehensive plagiarism checking included.
✅ Pros
- Highest accuracy in independent testing (98.7%)
- Plagiarism + AI content detection in one tool
- Commercial rights on paid plans
- Team management and API access
⚠️ Cons
- Pay-as-you-go model can add up for high volume
- No completely free tier (trial only)
- Can be expensive for individual users
Pricing: $0.01/100 words (pay-as-you-go)
2. GPTZero — Best for Educators & Students
Trusted by 3M+ teachers and built by a former Princeton student.
Purpose-built for academic integrity with classroom-friendly features.
✅ Pros
- Class dashboards and writing feedback tools
- Batch file upload and Chrome extension
- 10,000 free words monthly
- Student-friendly interface
⚠️ Cons
- Limited to text content only
- No image or code detection
- Can have false positives with complex writing
Pricing: Free–$10/mo • Current Deal: 10K free words/month
3. Copyleaks — Best for Enterprise & Universities
99%+ accuracy, LMS integrations (Canvas, Moodle), military-grade security.
Enterprise-grade solution with comprehensive compliance and security features.
✅ Pros
- Highest accuracy rating (99.1%)
- Multilingual detection capabilities
- Enterprise-grade security and compliance
- LMS integrations for educational institutions
⚠️ Cons
- Higher pricing for small teams
- Custom pricing (no transparent rates)
- May be overkill for individual users
Pricing: Custom enterprise pricing
4. Winston AI — Best for Publishers & Long-Form
Specialized in detecting Claude, GPT-4, and Llama 3 — 99.98% claimed accuracy.
Optimized for long-form content with PDF/Word upload support.
✅ Pros
- PDF/Word upload support
- Readability score included
- Plagiarism checker included
- 2,000 free words to start
⚠️ Cons
- Limited free tier
- Can be slower with very long documents
Pricing: From $9.99/mo • Current Deal: 2,000 free words
5. Writer.com Detector — Best for Quick Free Checks
100% free, no signup, unlimited scans, and perfect for instant checks.
Simple, fast, and effective for quick content verification.
✅ Pros
- 100% free with no signup required
- Clean interface with sentence highlighting
- Supports up to 5,000 characters
- Instant results
⚠️ Cons
- Limited to 5,000 characters
- No advanced features or history
- No batch processing
Pricing: Free (always)
6. Sapling AI Detector — Best for Developers & API
Chrome extension, Google Docs add-on, powerful API.
Developer-focused with professional integration options.
✅ Pros
- Powerful API for custom integrations
- Real-time detection capabilities
- Chrome extension and Google Docs add-on
- Team management features
⚠️ Cons
- Technical setup required for API
- Limited free tier
- Lower accuracy than top competitors
Pricing: Free–$25/mo
7. Content at Scale Detector — Best for Long-Form SEO Content
Free tool optimized for 2,000–10,000 word articles.
Built specifically for detecting AI in SEO content and blog posts.
✅ Pros
- Optimized for long-form content
- Readability score included
- Confidence percentage displayed
- No signup required
⚠️ Cons
- Limited to basic detection
- No batch processing
Pricing: Free
8. ZeroGPT — Fastest Free Option
Instant results with highlighted AI sentences and percentage score.
Quick and simple detection for immediate verification.
✅ Pros
- 100% free with unlimited scans
- Simple, no-signup interface
- Highlighted AI sentences
- Very fast processing
⚠️ Cons
- Lower accuracy than paid tools
- Limited to basic detection features
- Can have false positives
Pricing: Free
9. Hugging Face Open-Source Detectors — Best for Developers
Free open-source models (OpenAI Detector, DeBERTa, etc.) you can run yourself.
Maximum flexibility and control for technical users.
✅ Pros
- Fully customizable and self-hostable
- No limits on usage or customization
- Deploy on your own server
- Complete control over detection process
⚠️ Cons
- Requires technical knowledge to deploy
- No user interface out of the box
- Setup and maintenance required
Pricing: Free (open-source)
10. Quillbot Detector — Best for Students & Casual Use
Free detector built into the popular paraphrasing tool.
Convenient for students already using Quillbot for writing.
✅ Pros
- Simple interface that works alongside paraphraser
- 100% free with unlimited usage
- Easy to use for beginners
- No signup required
⚠️ Cons
- Limited advanced features
- Basic detection capabilities only
- Lower accuracy than specialized tools
Pricing: Free
Frequently Asked Questions
Are AI detectors 100% accurate?
No tool is perfect. Top tools like Originality.ai and Copyleaks reach 98–99%+ accuracy, but short or heavily edited text can cause false positives or negatives.
Can AI content be undetectable?
Yes. Tools like StealthGPT, BypassGPT, and skilled human editing can reduce detection rates significantly, though no method is 100% reliable.
Which is best for Google's Helpful Content Update?
Originality.ai combined with human editing is the safest approach for passing both AI detectors and Google's quality guidelines.
Do free AI detectors work well?
Free tools like Writer.com and ZeroGPT work for basic checks but paid tools offer higher accuracy and more features for professional use.
Final Verdict
Most creators use two tools: Originality.ai or Copyleaks for enterprise needs → Writer.com or ZeroGPT for quick free checks.