Writing
Originality.ai
AI detector, plagiarism checker, and content quality suite for writers, editors, and teams
Originality.ai is an AI content detection and content-quality platform: an AI checker tested against leading LLMs (GPT, Claude, Gemini, DeepSeek, Llama, and more) and trained on adversarial data to catch AI-paraphrased text, plus a plagiarism checker, grammar checker, readability checker, fact checker, and guideline checker in one suite. Deep Scan explains why text is flagged as AI and how to ethically edit it, Sentence Highlights show which parts are most likely AI, and a Chrome extension can replay writing in Google Docs to prove authorship. It also supports full-site URL scans, team management, and an API for enterprise use.
- Best for
- Publishers, content marketing teams, agencies, and educators who need to verify AI use, plagiarism, and content quality at scale — not just a single free AI checker
- Pricing
- Free (3 scans/day, AI detection only); Pro $12.95/mo (2,000 credits/mo, most popular); Enterprise $136.58/mo (15,000 credits/mo, API access, dedicated support)
Core features
- • AI Checker tested against leading LLMs
- • Plagiarism Checker
- • Grammar and Readability Checker
- • Fact Checker and Guideline Checker
- • Deep Scan with sentence-level AI highlights
- • Chrome extension with Writing Replay for proof of authorship
- • Full-site URL scans, team management, and API
Use cases
- 1. Check whether submitted content was written or edited by AI
- 2. Verify freelance or outsourced content is original before publishing
- 3. Scan an entire website by URL for AI-generated or plagiarized content
- 4. Show writing authorship in Google Docs for students or writers
- 5. Run content quality, grammar, and fact checks in one pass
How to use
Paste, upload, or enter a URL to scan, run the AI Checker (plus plagiarism, grammar, or fact-check scans as needed), then review sentence-level highlights and use Deep Scan to see why text was flagged and how to revise it.
Pricing plans
Basic
Free
- • 3 scans/day
- • 2,000-word scan limit
- • AI detection only
- • File upload (docx, pdf, doc)
Pro
$12.95/mo
- • 2,000 credits/month
- • Full site scans by URL
- • Team management, tagging
- • Chrome extension
Enterprise
$136.58/mo
- • 15,000 credits/month
- • 365-day scan history
- • API access
- • Dedicated Customer Success Manager
Where it holds up
- Continuously trained against adversarial/paraphrasing tools (e.g. Quillbot) to catch hidden AI edits
- One suite covers AI detection, plagiarism, grammar, readability, and fact-checking
- Deep Scan and Sentence Highlights explain exactly why text was flagged, not just a score
- Free tier available for quick checks, no subscription required
Where it falls short
- Free tier is limited to 3 scans/day and AI detection only
- Full feature set (full-site scans, API, team management) requires Pro or Enterprise
- Credit-based usage means heavy scanning volume needs a higher tier
This link may be an affiliate link — see our disclosure.