Best AI Detectors in 2026

Last updated: February 2026

The best AI detectors in 2026 are GPTZero (most accurate at 99%+, $15-35/month), Originality.ai (best for content marketers with plagiarism checking, $12.95/month), Turnitin (academic standard with LMS integration, institutional pricing), and Winston AI (includes AI image detection, $12-19/month). Free options include ZeroGPT (no signup), QuillBot (1,200 words free), and limited tiers of most paid tools.

The AI detector market is booming. Projected to hit $13.68 billion by 2035, up from $1.08 billion in 2025. Education leads adoption, but publishers, marketers, and HR teams are catching up.

No detector is perfect. Accuracy ranges from 65-95% depending on the tool and content type. Paraphrased or edited AI content is harder to catch. False positives remain a real concern, especially for non-native English speakers.

This guide covers 12+ AI detectors and when each makes sense.

AI Detector Comparison Table 2026

How AI Detectors Work

Before diving into specific tools, here's what's happening under the hood.

Perplexity Analysis Measures how predictable text is. AI-generated content has low perplexity. Smooth, expected word choices. Human writing has higher perplexity. Unexpected phrases, creative flourishes.

Burstiness Analysis Measures sentence variety. Humans write in bursts. Short punchy sentences mixed with longer elaborate ones. AI tends toward uniform sentence length and structure.

Pattern Recognition Machine learning models trained on millions of AI and human samples. They identify stylistic fingerprints unique to different AI models.

The Catch Formal academic writing naturally has low perplexity. Technical docs look like AI. Non-native English speakers get flagged more often. Even the Declaration of Independence triggers some detectors.

The Top Tier

GPTZero

The accuracy leader. First detector to reliably classify mixed human/AI content. Strong integrations with educational platforms. The benchmark that other detectors try to beat.

Best for: Education, mixed document detection, multilingual content

Key features:

• 99%+ accuracy on pure AI content
• 96.5% accuracy on mixed documents
• Paraphraser Shield for altered AI content
• Canvas, Moodle, Google Classroom integrations
• Chrome extension and Google Docs add-on
• Supports English, German, Portuguese, French, Spanish

Pricing:

• Free: 10,000 words/month
• Essential: $15/month (150,000 words)
• Premium: $24/month (300,000 words)
• Professional: $35/month (500,000 words)
• API: $45/month (300,000 words)

Strengths: Industry-leading accuracy, excellent mixed content detection, strong LMS integrations Weaknesses: Higher pricing than some alternatives, may struggle with heavily edited AI content

Choose GPTZero when: You need the most reliable detection, especially for documents mixing human and AI writing. Best for educators and institutions.

Originality.ai

The content marketer's choice. Combines AI detection with plagiarism checking, fact checking, and readability scoring. Built for teams publishing at scale.

Best for: Content marketers, SEO professionals, publishers

Key features:

• AI detection for ChatGPT, GPT-4o, Gemini, Claude 3.5, Llama
• Plagiarism checker (outperforms Grammarly/Copyscape)
• Fact checker and readability scoring
• Team management for collaborative workflows
• Chrome extension (50 free credits on install)
• API access for automation

Pricing:

• Pay-as-you-go: $30 one-time (3,000 credits, 2-year expiry)
• Pro: $12.95/month annual (2,000 monthly credits)
• Enterprise: $136.58/month annual (15,000 monthly credits)
• 1 credit = 100 words

Strengths: All-in-one solution, excellent for content teams, flexible pay-as-you-go option, strong API Weaknesses: Credit system can be confusing, plagiarism check costs extra credits

Choose Originality.ai when: You're publishing content and need AI detection plus plagiarism checking in one tool. Best for marketing teams and agencies.

Turnitin

The academic standard. Already embedded in most university workflows. AI detection is an add-on to existing plagiarism infrastructure. If your institution uses Turnitin, this is the path of least resistance.

Best for: Academic institutions with existing Turnitin licenses

Key features:

• Integrated into existing Similarity Reports
• Deep LMS integration (Canvas, Blackboard, Moodle)
• Institution-wide analytics and reporting
• Designed for grading workflows
• Low false positive rate (less than 1%)

Pricing:

• Institutional licensing only (no individual purchases)
• K-12: $1,000-5,000/year
• Universities: $5,000-20,000/year
• AI detection is add-on to base plagiarism license

Accuracy:

• Claimed: 98%
• Actual (per Chief Product Officer): ~85%
• 85-98% on pure AI output
• 40-70% on edited/paraphrased AI content

Strengths: Already embedded in educational infrastructure, low false positive rate, comprehensive reporting Weaknesses: No individual access, expensive for smaller institutions, accuracy drops on edited content

Choose Turnitin when: Your institution already uses it and wants AI detection integrated into existing workflows.

Winston AI

The publisher's tool. Highest claimed accuracy rate plus unique AI image detection. Catches AI-generated images from Midjourney, DALL-E, and Stable Diffusion alongside text.

Best for: Publishers, media organizations, institutions needing image verification

Key features:

• 99.98% claimed accuracy (independent testing: ~95%)
• AI image/deepfake detection (Midjourney, DALL-E, Stable Diffusion)
• OCR for scanned documents and handwriting
• Paraphrased content detection (including Quillbot)
• Color-coded predictability map
• Multilingual support

Pricing:

• Free Trial: Includes AI image detection
• Essential: $12/month annual (80,000 words)
• Advanced: $19/month (AI + plagiarism detection)

Strengths: Unique image/deepfake detection, highest claimed accuracy, OCR capability, good paraphrase detection Weaknesses: Smaller user base, limited integrations, premium required for plagiarism checking

Choose Winston AI when: You need to verify images as well as text. Best for media organizations and publishers.

Strong Alternatives

Copyleaks

The multilingual leader. Supports 30+ languages, more than any competitor. Strong LMS integrations make it popular with international academic institutions.

Best for: Global teams, international schools, multilingual content

Key features:

• AI detection for ChatGPT, Gemini, Deepseek, Claude
• 30+ language support (industry-leading)
• Combined AI and plagiarism reports
• LMS integration (Canvas, Blackboard)
• Code plagiarism detection
• API access

Pricing:

• Free Trial: 5 credits
• AI Detector Only: $7.99/month (1,200 credits)
• Plagiarism Only: $8.99/month (1,200 credits)
• Personal: $13.99/month (both features)
• Pro: $74.99/month (advanced features)
• 1 credit = 1 word for AI detection

Accuracy:

• 98.8% on pure AI text
• 87.5% on mixed documents
• 11% false positive rate
• Drops to ~50% on paraphrased content

Strengths: Best multilingual support, strong LMS integrations, combined features, low entry price Weaknesses: Higher false positive rate, accuracy drops on paraphrasing, credit system expensive at scale

Choose Copyleaks when: You work across multiple languages or need strong LMS integration for international institutions.

Content at Scale AI Detector

Built for SEO. Specifically tuned for marketing content. Free basic detection. Part of a larger content creation platform.

Best for: SEO professionals, content marketers, blog publishers

Key features:

• Free basic AI detection
• Detailed breakdowns for long-form content
• WordPress and Shopify integrations
• Copyscape integration
• Keyword research and topic clusters
• Content optimization tools

Pricing:

• AI Detector Only: Free
• AI Detector + Humanizer: $49/month
• Full Platform: $39-1,199/month depending on volume

Accuracy: 92% with strong performance on SEO content

Strengths: Free tier, specifically tuned for marketing content, doesn't penalize optimized human writing Weaknesses: Less suitable for academic use, full platform expensive, detection secondary to content features

Choose Content at Scale when: You're focused on SEO content and want a free detector that understands marketing writing.

Sapling

The business communication tool. Combines AI detection with writing assistance. Sentence-level highlighting shows exactly which parts triggered detection.

Best for: Customer support, sales teams, business communication

Key features:

• Sentence-level AI highlighting
• Grammar and style improvements
• Message suggestions and snippets
• Chat assist for quick responses
• Two detection methods: full-text + per-sentence

Pricing:

• Free: 2,000 characters per check
• Pro Monthly: $25/month (50,000 characters)
• Pro Annual: $12/month (50,000 characters)
• API: $0.005/1,000 characters

Strengths: Combined writing assistant + detection, sentence-level insights, affordable API Weaknesses: Character limits (not word-based), less focused on pure detection, limited accuracy data

Choose Sapling when: You need AI detection alongside writing assistance for customer-facing communication.

Budget and Free Options

ZeroGPT

No signup required. Instant free checks. But accuracy is significantly lower than paid alternatives.

Best for: Quick, casual checks (not high-stakes decisions)

Key features:

• No signup for basic use
• All languages supported
• Batch file uploads (paid)
• Built-in paraphraser and summarizer

Pricing:

• Free: 15,000 characters/detection, 1,000 prompts/month
• Pro: $9.99/month (100,000 characters)

Accuracy:

• Claimed: 98.80%
• Independent testing: 73.8%
• 20.51% false positive rate
• 26.4% of pre-ChatGPT human essays flagged as AI

Strengths: No signup, affordable, multilingual Weaknesses: Low accuracy, high false positive rate, unreliable for serious use

Choose ZeroGPT when: You need a quick free check and won't base important decisions on the result.

QuillBot AI Detector

Free up to 1,200 words. Part of the popular paraphrasing tool. Good for students on a budget.

Best for: Students, casual users, budget-conscious writers

Key features:

• 100% free up to 1,200 words
• Line-by-line analysis
• Categories: AI-generated, AI-refined, human with AI assistance, purely human
• Bulk document uploads
• 6 languages supported

Pricing:

• Free: 1,200 words/check, no signup
• Premium Monthly: $19.95/month
• Premium Annual: $8.33/month ($99.95/year)

Accuracy: ~77% in independent testing

Strengths: Completely free for basic use, no signup, good category breakdown Weaknesses: Lower accuracy, 1,200 word limit, primarily a paraphrasing tool

Choose QuillBot when: You're a student wanting a free quick check before submitting.

Writer.com AI Detector

No signup needed. Paste text or URL. Fast results. Part of a larger enterprise writing platform.

Best for: Quick checks, enterprise teams using Writer.com

Key features:

• No signup for basic detection
• URL or text paste analysis
• Quick results (seconds)
• Team collaboration (up to 5 members)

Pricing:

• Free AI Detector: Basic detection, no signup
• Team: $18/user/month (500,000 words)
• Enterprise: Custom pricing

Strengths: No signup, fast, good for teams Weaknesses: Limited accuracy, no sentence-level detection, struggles with mixed content

Choose Writer.com when: You need a quick free check or your team already uses Writer.com.

Scribbr AI Detector

Pay-per-use model. Good for occasional checks. Powered by QuillBot technology.

Best for: Students checking papers before submission

Key features:

• 1,200 words free
• Sentence-level AI probability
• Paragraph-level feedback
• Classifies: fully human, fully AI, or mixed
• English, German, French, Spanish

Pricing:

• Free: Up to 1,200 words
• Up to 7,500 words: $19.95
• Up to 50,000 words: $29.95
• Over 50,000 words: $39.95

Accuracy: ~77% (shared QuillBot technology)

Strengths: Pay-per-use, trusted academic brand, good for occasional checks Weaknesses: Low free limit, accuracy concerns, limited languages

Choose Scribbr when: You need occasional one-off checks and prefer pay-per-use over subscription.

Specialized Options

Crossplag

100+ language support. Unlimited words on premium tier. Academic focus with confidence percentages.

Best for: International institutions, 100+ language support needs

Key features:

• ML + NLP detection
• Confidence percentage ratings
• 100+ languages (most in industry)
• Combined plagiarism detection
• API access on premium

Pricing:

• Free: Limited (requires account)
• Basic: $15/month (10,000 words)
• Standard: $50/month (50,000 words)
• Premium: $100/month (unlimited)
• Pay-as-you-go: $0.01/credit (100 words)

Strengths: Widest language support, unlimited on premium, pay-as-you-go option Weaknesses: Less established, limited accuracy benchmarks

Choose Crossplag when: You need the broadest language support or unlimited detection volume.

Undetectable.ai

Not a detector. A checker and humanizer. Tests content against multiple detectors, then helps rewrite to pass. Controversial for academic use.

Best for: Content creators verifying AI content passes detection

Key features:

• Multi-detector checker (tests against GPTZero, Originality, etc.)
• AI Humanizer to transform flagged content
• 9 writing modes (University, Journalist, Marketing, etc.)
• 50+ languages
• Refund guarantee if humanized content gets flagged

Pricing:

• Entry Annual: $5/month ($60/year, 20,000 words)
• Monthly: $19/month (20,000 words)

Strengths: Tests against multiple detectors, multiple writing modes, refund guarantee Weaknesses: Enables bypassing detection, ethical concerns for academic use

Choose Undetectable.ai when: You use AI for content and want to verify it passes detection. Not for academic integrity.

Use Cases by Industry

Best for Education

1. GPTZero (highest accuracy, LMS integrations)
2. Turnitin (already embedded in workflows)
3. Copyleaks (multilingual, LMS integration)

Best for Content Marketing

1. Originality.ai (AI + plagiarism + fact check)
2. Content at Scale (SEO-focused, free tier)
3. Winston AI (high accuracy, team features)

Best for Publishers

1. Winston AI (text + image detection)
2. Originality.ai (comprehensive checking)
3. GPTZero (accuracy leader)

Best for International Teams

1. Crossplag (100+ languages)
2. Copyleaks (30+ languages)
3. GPTZero (5 major languages)

Best Free Options

1. Content at Scale (free detector, SEO focus)
2. ZeroGPT (no signup, quick checks)
3. QuillBot (1,200 words free)

Accuracy Reality Check

No AI detector is perfect. Here's what the data shows.

Key findings:

• Accuracy drops 20-50% on paraphrased or edited AI content
• Stanford research: 61%+ of non-native English essays misclassified as AI
• With 22.35 million first-year US essays annually, even 1% false positive = 223,500 wrongly flagged
• UCLA and other UC campuses declined Turnitin AI detection due to accuracy concerns

Bottom line: Use AI detectors as one signal, not the sole basis for decisions.

How to Choose

Start with your use case:

Educator/Institution: GPTZero (accuracy) or Turnitin (if already using) Content Marketer: Originality.ai (all-in-one) or Content at Scale (free) Publisher: Winston AI (text + images) or Originality.ai International Team: Copyleaks (30+ languages) or Crossplag (100+) Student: QuillBot (free) or Scribbr (pay-per-use) Quick Check: ZeroGPT or Writer.com (no signup)

Then consider:

• Accuracy needs: High-stakes = GPTZero/Originality. Casual = free options work.
• Budget: Free tiers handle light use. $15-25/month unlocks serious capability.
• Integration: Need LMS? GPTZero, Turnitin, or Copyleaks.
• Languages: Working globally? Crossplag or Copyleaks.

Which AI Detector Should You Choose?

GPTZero leads on accuracy. Originality.ai wins for content marketers. Turnitin makes sense if your institution already uses it. Winston AI stands alone on image detection.

Free options (ZeroGPT, Content at Scale, QuillBot) work for casual checks. Don't base important decisions on them.

The $15-25/month tier unlocks reliable detection. Most power users pick one primary tool and stick with it.

Remember: no detector is perfect. Use results as one input, not the final verdict.

FAQs About AI Detectors

What is the most accurate AI detector in 2026?

GPTZero leads with 99%+ accuracy on pure AI content and 96.5% on mixed human/AI documents. Winston AI claims 99.98% accuracy. Originality.ai achieves 96% in independent testing. No detector is 100% accurate, especially on edited or paraphrased AI content.

Are AI detectors free?

Most offer free tiers with limits. GPTZero offers 10,000 words/month free. ZeroGPT and Writer.com require no signup for basic checks. QuillBot offers 1,200 words free. Paid plans typically cost $10-25/month for full features.

Can AI detectors be wrong?

Yes. Studies show accuracy ranges from 65-90% depending on the tool and content type. False positive rates vary from under 1% (Turnitin) to over 20% (ZeroGPT). Non-native English writing and formal academic text trigger more false positives. Never use AI detection as the sole basis for decisions.

Do AI detectors work on paraphrased content?

Accuracy drops significantly. Copyleaks falls to ~50% on paraphrased content. GPTZero's Paraphraser Shield helps but isn't perfect. Heavily edited AI content is harder to detect than raw AI output.

Which AI detector is best for schools?

Turnitin for institutions already using it (integrated into LMS). GPTZero for standalone use with Canvas/Moodle integration. Copyleaks for international schools needing 30+ language support. All offer educational pricing.

Can AI detectors detect ChatGPT and Claude?

Yes. Major detectors support GPT-4, GPT-5, Claude 3.5, Gemini, Llama, and other popular models. Detection accuracy is highest on raw, unedited output from these models. Newer models may temporarily evade detection until detectors update.

Automate AI Detection Workflows

Checking content manually is fine for one-off use. But if you're reviewing content at scale, you need automation.

With Miniloop, you can build workflows that:

• Automatically scan incoming content submissions through AI detection APIs
• Route flagged content to human reviewers
• Generate reports on AI usage across your content pipeline
• Integrate detection into your publishing workflow

Describe what you want in plain English. Miniloop generates the workflow. Try it free or browse templates to get started.

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