Factual Verifiability Checker: Will AI Trust Your Claims?

What Is Factual Verifiability?

Factual verifiability is how easily a reader, or an AI engine, can confirm that the claims on your page are true. It depends on whether your statements point to credible sources, attribute data to its origin, and expose the methodology behind any figures. Content that is easy to verify is treated as more trustworthy and is far more likely to be cited.

What Glippy Checks

• External citations - links from the main content to other sites, ignoring social, sharing and app-store links, with at least one authoritative source among them
• Source attribution - "according to" and its Dutch, German and French equivalents, numbered footnotes, author-year citations such as (Smith, 2023), DOIs, and "et al."
• Citation markup - <cite> elements, footnote links, and a references or sources section
• Methodology transparency - sample sizes, margins of error, peer review, "how we tested", or a link to a methodology page
• Authoritative sources - links to government, academic, research and standards sites (.gov, .edu, europa.eu, WHO, DOI, arXiv, PubMed, W3C, ISO, national statistics offices), weighted above general .org and Wikipedia links
• Verifiable claims - facts a buyer can check: certifications and standards (ISO 9001, SOC 2, CE, B Corp, Trusted Shops), ratings on named review platforms or AggregateRating markup, a specification table, product identifiers (GTIN, EAN, MPN, SKU, model number), warranty terms with a duration, and links to security or trust pages

Expectations follow the page type. Articles are scored on external citations and authoritative sources. Product and landing pages are scored on verifiable claims instead, because a shop page proves itself with certifications, ratings and identifiers rather than footnotes. These three are scored only when the page type is clear (from schema.org markup, shop controls or a dated article, for example); when it is not, they are shown with the reason and not scored. Citation markup counts as a bonus on every page. Source attribution and methodology transparency are beta checks: shown for guidance, not scored. Checks that are not expected on a page type count as a bonus: they add points when present and cost nothing when absent.

Why Verifiability Matters for AI Citations

AI engines stake their credibility on the accuracy of what they surface, so they prefer claims they can trace back to authoritative sources. Adding external citations, clear attribution, and methodology signals makes your content safer to cite, which is exactly what improves your odds of being referenced in AI answers.