Crossref Similarity Check

Crossref member access to iThenticate similarity reports

Updated August 2, 2026

Crossref Similarity Check Overview

Crossref Similarity Check gives eligible Crossref members reduced-rate access to Turnitin’s iThenticate comparison service. Participating publishers contribute links to their published full text, then submit manuscripts through iThenticate or a supported submission-system API. A similarity report highlights matching passages for editorial review; it does not by itself determine whether plagiarism occurred.

Key Features

  • iThenticate reports: Generate similarity scores and highlighted text matches against scholarly and web content.
  • Publisher corpus: Participating members contribute current and archival full text to the comparison database.
  • Submission options: Upload manuscripts in iThenticate or use a supported manuscript-system API.
  • Unlimited organizational users: The member service includes unlimited users within the participating organization.
  • Member eligibility: Access requires active DOI publishing and suitable full-text URLs in Crossref metadata.

Pricing

Offer Current price Billing and scope
Annual Similarity Check service fee $40 to $10,000 per year 20% of the member's annual Crossref membership fee; tier depends on publishing revenue or expenses
1-100 documents per year $0 per document Documents up to 25,000 words
101-2,000 documents per year $0.75 per document Documents up to 25,000 words
2,001-25,000 documents per year $0.65 per document Documents up to 25,000 words
25,001-50,000 documents per year $0.55 per document Documents up to 25,000 words
50,001-100,000 documents per year $0.45 per document Documents up to 25,000 words
100,001-200,000 documents per year $0.30 per document Documents up to 25,000 words
More than 200,001 documents per year $0.25 per document Documents up to 25,000 words; threshold wording follows the official table

Participation also requires Crossref membership and active DOI publishing with full-text URLs. The annual service fee tiers run from $40 to $10,000 because the fee is 20% of the member's separate $200-$50,000 membership fee.

Pricing source: https://www.crossref.org/fees/#similarity-check-fees

Pros

  • Scholarly focus: The service is designed for editorial screening against published academic content.
  • Transparent formula: Crossref publishes annual and per-document fee rules.
  • Workflow integration: Eligible publishers can connect checks to manuscript-submission systems.

Cons

  • Membership required: Independent users cannot buy this Crossref service without qualifying membership and publishing activity.
  • Two-part cost: Organizations pay an annual service fee plus volume-based document charges.
  • Human judgment required: A similarity score flags overlap but does not establish plagiarism on its own.