Link Equity and PageRank: What Is Known

Link equity and PageRank is the idea that links between pages help a search engine understand what the pages are about and which of them are more helpful. Google confirms that PageRank is one of its ranking systems, but it publishes neither a formula nor numbers. So below we separate three layers: what Google’s documentation says, what belongs to third-party metrics such as DR and DA, and what is a simplified picture that is handy to keep in mind but must not be presented as fact.

What the documentation says

In the guide to ranking systems, Google writes that it has various systems that understand how pages link to each other as a way to determine what pages are about and which might be most helpful in response to a query, and names PageRank among them. That is all it says directly: there is no “authority × relevance ÷ number of links” formula, no thresholds, no comparison of links from body text, sidebar and footer.

A practical conclusion follows: any numbers and coefficients you meet (“a link from the body text weighs twice as much”) are hypotheses or observations of their authors, not documented behavior. You can use them as a working hypothesis in your own project, testing on data, but not as an argument in a “this is how Google counts” dispute.

DR, DA and other third-party metrics

DR and DA are indicators from third-party services (Ahrefs and Moz); each computes them with its own model of the link graph. Google does not use them and never defines them. The metrics are useful for comparing sites within a single service and for a first screening of donor sites, but “a link from DR 80 beats a hundred links from DR 10” is not a conclusion from the documentation but an assumption. How to read such metrics honestly is covered in the lesson on link profile metrics.

What the documentation says about links

Links must be crawlable

According to the help page on crawlable links, Google can generally crawl a link only if it is an <a> element with an href attribute; most links in other formats won’t be parsed. A link the crawler does not see can neither help find a page nor connect it to another — whatever its “weight”.

Internal links: every page you care about should have at least one

The same page says: every page you care about should have a link from at least one other page on your site, link in context where it helps the reader, and there is no “magical ideal number” of links on a page (though if you think it is too many, it probably is). This is the one thing you can take from the documentation as a rule about distributing links inside a site. How to find pages left without links is in the lesson on navigation and the crawler tool; the anchors and context of links to a specific page are shown by internal link context.

Outbound links and rel attributes

The documentation on qualifying outbound links offers rel values to tell Google the relationship with the page you link to: sponsored for ads and paid placements, ugc for links in user-generated content (comments, forums), and nofollow when other values don’t apply and you’d rather Google not associate your site with the page or crawl it from your site. nofollow was previously recommended for paid links; it is still acceptable, though sponsored is preferred. How much “weight” each value passes or does not pass, the documentation does not say, so “nofollow passes no weight” as a number is not from the documentation. External links are not dangerous in themselves: Google writes that they can help establish trustworthiness, for example when citing sources. More on types is in the lesson on link types.

Paid links and exchanges are spam

In the spam policies, link spam is links to or from a site created primarily to manipulate rankings: buying and selling links for ranking purposes (money, goods, services, sending a product in exchange for an article with a link), excessive link exchanges and partner pages that exist only for cross-linking. For details see the lesson on spam policies, and for checking your own link profile see the backlink audit.

The simplified model: how to use it

The model “a link passes part of its value, and the more links a page has, the less each receives” is a historically convenient picture from the early work on PageRank. You can use it as a mental tool: if you want search to connect an important page with the rest of the site better, give it links from relevant places. But Google’s current computation is not published, so the model is an illustration, not a formula.

Checklist

1. Important pages are connected to the rest of the site by ordinary <a href> links.
2. There are no pages with no internal links pointing to them.
3. Paid and advertising links carry sponsored, user links carry ugc.
4. Decisions do not rest on “weight formulas” from blogs; hypotheses are tested on your own data.
5. DR and DA are used as comparative indicators within one service, not as a Google rating.

Mistakes

• Treating a weight formula from an article as documented.
• Giving money or goods for a link without marking it sponsored.
• Building menus on scripts without href, so the crawler does not see connections.
• Judging links only by DR and DA, ignoring relevance and origin.
• Removing all external links “so as not to lose weight”.

What next

Next come link types: how editorial, paid, user and internal links differ and how to qualify each. How to analyze an existing link profile is covered in the lessons on anchor text and toxic links.