What types of sources count as reliable on Wikipedia?

Wikipedia’s reliable-source standard is operationally specific. Sources must be independent of the subject, secondary (not the subject’s own output), published, professionally edited, and have a reputation for fact-checking and accuracy. The classification below shows which types qualify and which do not.

Sources that qualify

Major newspapers with established editorial standards

The Wall Street Journal, Financial Times, Bloomberg, Reuters, the New York Times, the Washington Post, the Associated Press, and their international equivalents. Coverage must address the subject directly and in depth, a brief mention in an unrelated story does not count.

Academic journals and peer-reviewed articles

Strong for any factual claim within their field. The peer-review process satisfies Wikipedia’s fact-checking requirement.

Books from established publishers

Publishers with independent editorial processes qualify. Self-published books do not.

Authoritative reference works

Encyclopaedia Britannica for general subjects; specialist encyclopedias and handbooks in their fields.

Trade publications with professional editorial standards

Evaluated case by case. A trade outlet counts when it has staff editors, a fact-checking process, and a reputation for accuracy, not when it primarily publishes contributed or sponsored material.

Sources that do not qualify

• Press releases and wire syndications of company announcements, explicitly excluded; they cannot support notability claims even when reprinted by major outlets.
• Sponsored content and native advertising, not editorially independent.
• The company’s own website, annual reports, and official materials, primary sources; useful only for uncontested basic facts, not for establishing notability.
• Social media posts and personal pages, self-published; excluded by Wikipedia’s verifiability policy.
• Blogs and forums, self-published unless the blog is a recognized publication with editorial oversight.
• Routine business coverage, brief announcements of funding rounds, personnel changes, or product launches do not count as significant coverage even when published in qualifying outlets.

Why this matters for notability

Wikipedia’s general notability guideline requires significant coverage in multiple reliable, independent, secondary sources. There is no fixed number of sources required, the assessment is qualitative, weighing the substance, reliability, independence, and directness of each piece. At the readiness stage, Five Blocks catalogs the existing coverage against this standard to determine whether an article is viable before any drafting begins.