Wikipedia citation: How sources power accuracy and trust on the free encyclopedia

When you see a fact on Wikipedia, it didn’t just appear—it was Wikipedia citation, the system that requires every claim to be backed by a published, reliable source. Also known as sourcing policy, it’s what keeps Wikipedia from becoming a collection of opinions. Without citations, Wikipedia wouldn’t be trusted by students, researchers, or even major news outlets that rely on it for quick facts. This isn’t about just adding footnotes—it’s about building a chain of evidence anyone can check.

Behind every solid Wikipedia article is a network of reliable sources, published materials like peer-reviewed journals, books from reputable publishers, and established news organizations. Also known as verifiable references, these are the backbone of Wikipedia’s credibility. But not every source counts. A blog post, a personal website, or an unpublished thesis won’t cut it. Even academic preprints, research papers shared before peer review. Also known as unreviewed manuscripts, they’re banned because they haven’t been checked by experts yet. The rule is simple: if it’s not published and reviewed, it’s not trusted. This is why editors fight over whether a newspaper article from 1998 is still valid, or if a university’s own press release qualifies as a source.

Wikipedia’s citation rules aren’t set by a single person—they’re shaped by thousands of volunteers who debate what counts as reliable. Tools like the Wikipedia Library, a free access program that gives editors legal access to paywalled academic journals and archives. Also known as research access portal, it helps editors find the sources they need without paying a dime. And when someone adds a bad citation, bots and editors jump in to fix it. The whole system exists because Wikipedia knows that trust isn’t earned by saying "I’m right"—it’s earned by showing proof.

What you’ll find below are real stories about how citations shape Wikipedia—from teachers turning student research into public knowledge, to journalists using the site’s tools to find hard-to-access sources. You’ll see how citation errors made headlines, how new editors learn to cite properly, and why some of the most-viewed articles on Wikipedia are the ones with the tightest sourcing. This isn’t just about formatting references. It’s about who gets to decide what’s true—and how the world’s largest encyclopedia stays grounded in facts.