Criterion CheckWise AI Originality.ai
CategoryAI Detection & Plagiarism CheckingAI Detection & Plagiarism Checking
In one sentenceAn independent document-analysis service that runs an AI-writing check and a similarity (plagiarism) check on the same upload.An AI content detector and plagiarism checker aimed at publishers, agencies, writers and educators.
Problem it solvesGives students, researchers, writers and businesses a quick, pay-per-check way to see whether a document shows AI-writing signals or closely matches existing sources, without a subscription.Helps content teams and educators check whether text may be AI-generated or plagiarised before publishing or grading it.
Free planNoYes
Developer APINoYes — docs
Open sourceNoNo
PlatformsWebWeb, Chrome extension, Google Docs, Firefox, API
Pricing (summary)Each account gets 1 free check (AI and similarity reports) until 1 January 2027, with no credit card. After that you buy one-time token packs: Starter $3 for 1 check, Plus $25 for 10 checks, Business $200 for 100 checks. Tokens are valid for 30 days; there is no subscription.
Checked 2026-10-19		A free Basic tier offers limited AI-detection scans per day without a subscription; paid Pro and Enterprise plans use monthly credits and add plagiarism and other checks, the Chrome extension, team features and (on Enterprise) API access, and one-time credit purchases are also available. The site says there is no free trial. Verify current plans on Originality.ai's pricing page.
Checked 2026-10-13
Strengths
  • AI analysis and similarity check combined in one check
  • Simple per-check pricing with no subscription
  • Clear data-handling statements: own server, no training on documents, 90-day purge
  • Says plainly that AI detection is probabilistic
  • Combines AI detection, plagiarism, fact-checking and readability tools in one product
  • Team management, scan history and an API suit agencies and publishers
  • The vendor openly advises that an AI score should be one signal among several, with a human in the loop
Limitations
  • AI detection can produce false positives and false negatives — the site says a score is an indicator, never proof
  • The size and scope of the similarity index are not described
  • No API or LMS integrations are listed
  • Purchased tokens are valid for 30 days
  • Supported languages are not stated
  • Detection results are probabilistic and can produce false positives; Originality.ai itself says a score shouldn't be used alone for academic integrity discipline, so it should never be the sole basis for academic or disciplinary decisions
  • The free Basic tier is limited to AI detection with a small daily scan and word allowance
  • Text entered into the free tool may be used for training unless you have an account and opt out