Core SEO Concepts
PageRank
Google's original algorithm for ranking web pages, based on the idea that links act as votes, with pages linked to by many high-quality pages themselves considered high quality.
What Is PageRank?
PageRank is the foundational algorithm Google's founders, Larry Page and Sergey Brin, developed in the late 1990s as part of the original technology underlying Google Search. Its core insight was that hyperlinks between web pages could be treated mathematically like votes: a page linked to by many other pages is likely important, and crucially, a link from a page that is itself considered important (because many pages link to it) should count for more than a link from an unimportant page. This recursive, weighted-voting concept — links from authoritative pages carrying more influence than links from obscure ones — became the conceptual foundation for how search engines have thought about backlinks ever since, even as the actual ranking algorithms have grown vastly more sophisticated and incorporate hundreds of additional signals. It's worth distinguishing the PageRank concept from the old public "PageRank Toolbar" score, a visible 0–10 score Google once displayed to the public via a browser toolbar — that public-facing display was discontinued years ago, even though the underlying link-based ranking principles Google uses internally remain very much alive in some evolved form.
Why PageRank Matters for SEO
The conceptual origin of link-based ranking
Nearly every modern link-based SEO concept — backlinks, domain authority, link equity — traces its logic back to PageRank's original weighted-voting premise.
Explains why not all links are equal
PageRank's core mechanism is why a link from an authoritative page carries more weight than a link from an obscure one, a principle that still holds broadly true today.
Historical context for modern link-building strategy
Understanding PageRank helps explain why relevance, authority, and link diversity matter so much in current SEO practice, even though the underlying algorithm has evolved far beyond its original form.
A Simple Example
Under the original PageRank logic, a link from a globally recognized, heavily-linked-to news outlet would pass substantially more ranking value than a link from a personal blog with almost no other pages linking to it — not because of any special rule about news sites specifically, but because the news outlet's own high PageRank (from being linked to so much itself) flows through, in reduced but still meaningful amounts, to whatever it links to.
Best Practices
- Understand PageRank as historical and conceptual context, not a metric to directly measure or chase today.
- Apply the underlying principle — prioritize links from genuinely authoritative, well-linked pages — to modern link-building strategy.
- Avoid confusing the discontinued public PageRank Toolbar score with the internal algorithmic concept, which Google has continued to evolve.
Common Mistakes to Avoid
- Searching for or trying to check a "PageRank score" today, since the public toolbar display no longer exists.
- Assuming PageRank as originally described in the 1990s is identical to how Google actually ranks pages now.
- Underestimating how much modern link-based signals still trace their logic back to this original concept.
Key Takeaways
- PageRank was Google's original algorithm treating links as weighted votes.
- Links from authoritative pages pass more value than links from obscure ones.
- The public PageRank Toolbar score was discontinued years ago.
- The underlying principle still conceptually underpins modern link-based ranking signals.