How Google Judges Backlink Quality in 2027

Google judges backlink quality by asking whether a link exists for readers or for rankings. Its published policies target links created mainly to manipulate search, and its systems can neutralize them. Google publishes no link quality score, so everything beyond those rules is inference.

What Does Google Actually Say About Backlink Quality?

Google defines link spam as creating links to or from a site “primarily for the purpose of manipulating search rankings.” Its examples include buying or selling links for ranking purposes, excessive link exchanges, and automated link building.

The same policy says buying and selling links is a normal part of the web economy, and that paid links are fine when qualified with a nofollow or sponsored value. Google’s SEO Starter Guide adds that the vast majority of new pages it finds each day are discovered through links.

That is the full documented picture. Intent, labelling, and discovery are stated. A numeric quality score is not.

How Does Google Handle Low-Quality Links?

Google said its December 2022 link spam update used SpamBrain for links for the first time. SpamBrain “can now detect both sites buying links, and sites used for the purpose of passing outgoing links,” according to Search Engine Land’s report. Google said rankings may change as spammy links are neutralized and the credit they passed is lost.

The update began December 14, 2022 and finished January 12, 2023, a 29-day rollout. Search Engine Land notes that neutralizing means not counting a link, not necessarily punishing a site. Gary Illyes made a similar point in 2019, saying Google can catch and ignore spam links, as Search Engine Journal reported.

The practical reading: a bad link is more likely to waste budget than to trigger a penalty. Sites that violate spam policies can still rank lower or drop out of results, so the exposure is real for anyone buying links at scale.

Do Backlinks Still Matter as a Ranking Signal?

Yes, with limits. Gary Illyes said at Pubcon Pro in 2023 that links matter but are not among the top three ranking factors, adding “I don’t agree it’s in the top three.” He described a site with no links that ranked first on content alone, found through its sitemap.

Vendor studies still find links alongside strong rankings. They cannot show how Google weighs them, because strong sites attract links, traffic, and mentions at the same time.

Source	Sample	Reported finding	Reading
Backlinko, April 2025 (via BuzzStream)	11.8 million results	#1 result had about 3.8x the backlinks of positions 2 to 10	Correlation; causation unclear
Semrush, 2025 (via BuzzStream)	16,298 keywords	URL traffic 0.33, link metrics 0.18	Links trail traffic as a correlate
Ahrefs, June 2025	Top 50 domains, 76.7M AI Overviews	Ahrefs Rank vs AI mentions: -0.12 (AI Overviews), 0.01 (ChatGPT), -0.34 (Perplexity)	Weak; small, domain-level sample
Google, Dec 2022	Link spam update	29-day rollout; spam links neutralized	Stated by Google

Only the last row comes from Google. The rest are vendor measurements of vendor metrics.

How Can You Grade Backlink Quality Claims? The Link Evidence Ladder

Most backlink quality checklists put authority, relevance, anchor text, and placement in a single list. Ahrefs’s help article on high-quality backlinks does this, listing each as a factor with the same confidence. A reader cannot tell which came from Google and which was inferred.

The Link Evidence Ladder fixes that by sorting every claim into one of four rungs before you act on it.

Rung	Example	Use it for	Limit
1. Google-stated	Link spam definition; rel values for paid links	Hard rules you must not break	Silent on weighting
2. Google staff comments	Illyes on links outside the top three	Direction of travel	Context-bound; no exact weights
3. Vendor studies	Backlinko, Semrush, Ahrefs correlations	Hypotheses to test	Correlation; vendor metrics
4. Practitioner rules	Relevance outweighs raw authority	Working checklists	Test on your own data

In practice, most of what agencies repeat about link quality sits on rungs three and four. That is fine, as long as the label travels with the claim.

Which Link Quality Signals Can You Test?

Is the Link Editorial?

Ahrefs’s help article says the most valuable links are editorially placed within content, while footer and sidebar links are less valuable. That is a rung four claim, but it matches Google’s rung one focus on purpose. Observed across client work, links that sit in a passage a reader would miss if it were deleted tend to be the ones worth keeping.

Is the Linking Page Relevant?

Ahrefs states that links from pages on the same topic carry more weight, and that mildly related links do no harm. No Google document puts a number on this. Test it by comparing rankings movement for relevant and loosely relevant placements.

Is the Anchor Text Natural?

Ahrefs advises varied, topic-relevant anchors because forced single-phrase anchors look unnatural. Treat that as a pattern check on your own profile. A report showing the same commercial phrase on every link deserves a second look.

Is the Link Labelled Correctly?

This is the one signal with rung one backing. Paid placements need a sponsored or nofollow value under Google’s policy. Ahrefs takes the view that nofollow links most likely pass no vote, so expect labelled links to carry audience value more than ranking value.

Does the Linking Site Exist for Readers?

SpamBrain was announced as detecting sites used to pass outgoing links. Be wary of sites with thin articles on unrelated topics that all link out to commercial pages. A pattern seen repeatedly in audits is a publisher whose recent posts have nothing in common except the clients linked.

Do Backlinks Affect AI Search Visibility?

Patrick Stox’s June 2025 Ahrefs study compared Ahrefs Rank with mention share across Google AI Overviews, ChatGPT, and Perplexity for the top 50 mentioned domains. The correlations were -0.12, 0.01, and -0.34, all weak, and none statistically significant.

Three caveats apply. The sample was only 50 heavily cited domains. The study measured one domain-level metric, not page-level links. The author also cites an earlier Ahrefs study where domain rating correlated at 0.326 with AI Overview brand mentions. The honest conclusion is that the link between backlinks and AI visibility is unsettled.

How Do You Review a Backlink Using the Ladder?

1. Step 1 Check rung one. Is the link bought, exchanged, or automated without a qualifying label? If yes, stop.
2. Step 2 Ask whether the link would exist without payment. If the answer depends on money, label it.
3. Step 3 Check that the page and audience match your topic.
4. Step 4 Look at the site’s recent posts and outbound links for a link-selling pattern.
5. Step 5 Record which rung supports every metric you quote, so reports separate fact from inference.

Frequently Asked Questions

How does Google judge backlink quality?

Google publishes no link quality score. Its documented rules target links made mainly to manipulate rankings, and its SpamBrain system can neutralize them. Everything else, such as relevance, placement, and anchor text, comes from vendor studies and practitioner experience, so treat those signals as hypotheses to test rather than confirmed ranking rules.

Does Google penalize sites for bad backlinks?

Usually the link is ignored, not punished. Google’s 2022 link spam update said spammy links are neutralized and the credit they passed is lost. Sites that buy or sell links for ranking purposes can still face lower rankings under Google’s spam policies, so the risk sits with the people who create the links.

Are nofollow links worthless for SEO?

Evidence is mixed. Google’s spam policy treats nofollow and sponsored values as the right way to qualify paid links, and Ahrefs says a nofollow link most likely passes no vote. Such links can still send readers to your page, so judge them on audience value as well as ranking value.

Is Domain Rating a Google metric?

No. Domain Rating belongs to Ahrefs, and other tools use their own scores built from their own crawls. Ahrefs found its rank metric correlated weakly with AI mentions in a 2025 study of 50 domains. Use vendor scores to compare prospects, never as a statement about how Google scores a link.

Do backlinks influence AI Overviews and AI search mentions?

The evidence so far is weak. An Ahrefs study of the top 50 mentioned domains found Ahrefs Rank correlated at -0.12 with Google AI Overviews and 0.01 with ChatGPT. The sample was small and domain-level only, so backlinks may matter through other paths, such as rankings.

Should you still use the disavow tool?

Rarely. Gary Illyes said in 2019 that Google can catch and ignore spam links, according to Search Engine Journal. The tool remains useful for links you are responsible for creating or after a manual action. Routine disavowing of random spam links is unlikely to help.

What Should You Do About Backlink Quality Before 2027?

Knowing how Google judges backlink quality means separating what it states from what the industry infers. Label every placement correctly, favour links a reader would follow, and tag each quality claim with its rung. Stay Digital Marketers assists brands with guest posting, press release distribution, SaaS backlinks, niche edits, multilingual backlinks, Wikipedia page creation, Google Knowledge Panel creation, and complete SEO services.