Free
$0One-time credits100 credits (10K words) once, with all checkers. The comparison table lists 60 credits (3 scans a day) instead. Official source 1 ↗ · Official source 2 ↗
Reviewed tool profile
Originality.ai
AI content detector and plagiarism checker for writers, publishers and schools, with fact, grammar and readability checks.
Sources checked
- Pricing
- Free plan with 100 one-time credits (10K words). Pro is $14.95 a month or $12.95 a month billed yearly ($155.40), with 2,000 credits (200K words) a month. Enterprise is $179 a month or $136.58 a month billed yearly ($1,638.96), with 15,000 credits a month and API access. Pay-as-you-go credits cost $30 for 3,000 and last 2 years. 1 credit covers 100 words of AI checking. Official source 1 ↗
- Available as
- Web app, plus extensions for Chrome, Google Docs and Firefox. · Moodle plugin, API, and an MCP connector for ChatGPT, Codex and Claude. Official source 1 ↗ · Official source 2 ↗ Official source 1 ↗ · Official source 2 ↗ · Official source 3 ↗
- Primary group
- Research & Data
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What it does
Originality.ai is an AI content detector and plagiarism checker from Collingwood, Ontario, built for writers, editors, publishers, agencies and schools. You paste text, upload a file or enter a URL, then run AI detection, plagiarism, fact, grammar, readability and content quality checks. Results show which sentences are likely AI, and Deep Scan explains why text was flagged. It also works in Chrome, Google Docs and Firefox, where Writer Replay shows how a document was typed, and inside ChatGPT and Claude through MCP.
Official source 1 ↗ · Official source 2 ↗ · Official source 3 ↗ · Official source 4 ↗Features
- AI detection. Classifies text as Likely AI, Original or Mixed with the 5.0 and 5.0 Max models, highlights the sentences most likely written by AI, and is trained to catch text reworded by tools like Quillbot. Official source 1 ↗ · Official source 2 ↗
- Plagiarism and fact checks. Scans text, uploaded files, single pages or whole websites for plagiarism, and checks facts to reduce AI hallucinations. Official source 1 ↗
- Writing quality tools. Grammar, readability, content quality score and guideline checkers, plus Deep Scan tips on how to edit flagged text so it reads more naturally. Official source 1 ↗ · Official source 2 ↗
- Writer Replay in Google Docs. Replays how a Google Doc was written character by character, flags auto-typing and shows who wrote or edited each section. Official source 1 ↗
- MCP for ChatGPT and Claude. Run Originality.ai scans from inside ChatGPT, Codex or Claude and open the full report in the app. Official source 1 ↗
- Team and API features. Team roles and shared reports on paid plans; API access on Enterprise. Official source 1 ↗ · Official source 2 ↗
Pricing & free limits
Pro
$14.95/monthMonthly, or $12.95/month billed yearly ($155.40)2,000 credits (200K words) a month, 30-day scan history, Deep Scan, Bulk Scan, file uploads, shareable and PDF reports, team management. Extra seats $9.95/month ($8.62 yearly). Official source 1 ↗
Enterprise
$179/monthMonthly, or $136.58/month billed yearly ($1,638.96)15,000 credits (1.5M words) a month, 1-year scan history, API access and priority support. Extra seats $24.95/month ($19.04 yearly). Official source 1 ↗
Pay as you go
$30One-time3,000 credits that expire 2 years after purchase if unused. Official source 1 ↗
Billing details
1 credit covers 100 words of AI checking; AI plus plagiarism uses 2 credits per 100 words. Official source 1 ↗
Subscription credits expire at the end of each month and are used before purchased credits. Official source 1 ↗
Prices are in USD and you can cancel anytime. Official source 1 ↗
Free access & limits
The free plan gives 100 credits per account, about 10K words of AI checks, once. Scan history and Deep Scan need a paid plan. Official source 1 ↗ · Official source 2 ↗
Best for & limitations
Check freelance articles for AI writing and plagiarism before publishing. Official source 1 ↗
Show that an essay or article is your own work with a Google Docs writing replay and shareable report. Official source 1 ↗
Scan a whole website for plagiarism by entering its URL. Official source 1 ↗
- Scores can be wrong. Originality.ai says false positives happen and an AI score should be one signal, with a human reviewer, not a final decision. Official source 1 ↗
- Free scans may train its models. Text pasted into the free detector may be used for training; account holders can opt out. Official source 1 ↗
- Credits run out monthly. Subscription credits expire at the end of each month, and API access is Enterprise only. Official source 1 ↗
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