How search engines evaluate links

In short

Three things decide what a link is worth: the authority of the source, its relevance to your topic, and the anchor text.

Since 2019 Google treats nofollow, sponsored and ugc as hints, not commands. It may still use those links.

Google now mostly ignores links it judges to be spam instead of punishing them, so the common cost of a bad link is wasted money.

No primary source supports a safe anchor text ratio or a safe number of links per month. Any figure you see is an industry rule of thumb.

A search engine has to decide, for every link it finds, whether to count it and how much. The exact weights are not public. What is known comes from Google’s own documentation, patents, the internal documents leaked in May 2024 and exhibits from the US antitrust trial.

Authority: who is linking

PageRank still exists. It passes value from page to page, so a link from a site that itself has strong links is worth more than one from a site nobody links to. The 2024 leak also lists a site-level authority field and shows that Google stores links in quality tiers, which suggests links from pages in its top index tier are treated as more valuable. The leak documents fields, not weights, so how much each one matters is not confirmed.

Relevance: does the link make sense

A link from a site about your topic carries more meaning than one from an unrelated site. The leaked documents include an anchor mismatch demotion, which points to Google checking whether the anchor text fits the page it points to.

Anchor text: what the link says

The words of the link tell the engine what the target page is about. That makes anchors powerful and risky. The Penguin update of 2012 was built to catch profiles stuffed with keyword anchors, and the leak includes fields for spikes of spammy anchor phrases.

Placement and attributes

A link in the main body of an article, where a reader would click it, is treated as stronger than one in a footer or sidebar. This idea comes from Google’s “reasonable surfer” patent.

Links can carry three labels:

nofollow: the site does not vouch for the target
sponsored: the link was paid for
ugc: the link was added by a user, as in comments

Since 2019 Google reads all three as hints. It decides for itself whether to use the link.

What happens to bad links

In most cases, nothing visible. Google’s SpamBrain system is designed to neutralise links it considers manipulative, which means they are ignored. A manual action, where a human reviewer penalises a site, still exists for clear patterns. Google has also said that once link value is neutralised it cannot be regained.

The practical point: the usual price of a poor link is the money spent on it.

What the evidence does not support

Two popular ideas have no primary source behind them. One is a safe ratio of anchor types. The other is a safe number of new links per month. Both depend on the market, so the working method is to study the profiles of the sites that already rank for your terms.

Other search engines

Bing uses links in a similar way and removed its disavow tool in October 2023. Yandex’s leaked code from 2023 shows factors for link age and penalties for sudden bursts. Naver barely uses links at all.

Common questions

What is a good Domain Rating for a link?

Domain Rating and Domain Authority are third-party estimates, not Google metrics, and they can be inflated. Real organic traffic and topical relevance are harder to fake and say more about a site.

Do nofollow links help?

They can. Google has treated nofollow as a hint since 2019, so it may count a nofollow link. Many of the strongest news sites only give nofollow links, and those still bring visibility and brand mentions.

Is there a safe percentage of exact-match anchors?

No published Google source gives one. The common advice of 1 to 5 percent is a heuristic drawn from practitioner experience. Compare your profile with the sites that rank in your market instead.