What Makes a Quality Backlink?
Everyone knows that backlinks are one of the major factors that make the SEO world go ’round, but there is often a great deal of misunderstanding when it comes to judging the quality of backlinks.
What makes a backlink a quality backlink? Which links are useful in helping to improve rankings?
This article will walk you through how we determine backlink quality based on our years of experience of building 1,000’s of links in almost every niche imaginable as well as clear up some common misconceptions when it comes to link evaluation.
The Holy Trinity of Link Quality
The main way to determine the quality of a link is by noting how much of the three factors of the Holy Trinity the backlink has.
The Holy Trinity includes relevance, authority, and power (we’ll be discussing each further).
The more of these things a link has, the better the link generally is. However, it’s a little more complicated than that.
First of all, a link doesn’t necessarily need to have high amounts of all three of these factors. For example, a link can be high on relevance but low on authority and power and still be a quality backlink.
Likewise, a link can be high on authority but low on relevance and power – this link can still provide tremendous benefit for your rankings.
You can think of these things on a sliding scale – the less of one factor the backlink has, the more you want it to have of the other factors.
In a perfect world, all of your links would have high amounts of all three factors. But that just isn’t possible (or natural). Natural sites get backlinks with wide discrepancies in the Holy Trinity, and most of these links play active roles in helping them rank. A site that only gets links with high relevance, power, and authority will be seen as unnatural and could be asking for trouble.
Second of all, there is more to judging the quality of backlinks than just the Holy Trinity (which we’ll also be getting to). This is a good way to simplify things to make quick judgements, but as you probably know by now, SEO is anything but simple.
Before we jump into these other factors, let’s first go a little deeper with the Holy Trinity of relevance, authority, and power.
We’ve got a whole article on backlink relevance along with a video walkthrough for those that really want to get into it, but we’ll go ahead and summarize it here as well.
A link is relevant for your website if the on-page factors are related to whatever it is linking to, and relevance can be checked with a tool like Ahrefs.
In other words, if there are keywords or related keywords in the linking page’s domain, URL, SEO title, meta description, h tags, content, and anchor text which are the same as or related to what it’s linking to, it becomes more relevant for what it’s linking to.
For example, if a page that is well optimized for plumbing links to a local plumber’s website, this is a very relevant backlink for that website.
Keep in mind what we said before – if a backlink is low on relevance, you’ll want it to have more authority or power. If it’s high on relevance, you might not care how much authority or power it has.
The second part of the Holy Trinity is the authority of a backlink. Authority is a little more convoluted than relevance, but it’s generally determined by the overall strength of a domain’s backlink profile along with more obscure factors like trust.
An example of an extremely authoritative link would be from a site like CNN. They have a massive backlink profile and are seen as a very trustworthy source of information by Google.
With Ahrefs, the authority of a site is noted by its DR (Domain Rating). You can see that CNN has a very high DR (and also an insane amount of backlinks). You can check authority with other services like Moz’s DA, Majestic’s CF/TF, and so on.
Although none of these provide a perfect picture of websites’ authority, we generally stick with Ahrefs’ DR to make judgements as it seems more accurate and more difficult for SEOs to manipulate.
Just like the previous section, a high authority link that’s low on power and relevance can be great for you just as a backlink that’s low on authority but higher on relevance and power can be. Remember to think about the Holy Trinity on a sliding scale.
Power is the most straightforward of the three metrics that comprise the Holy Trinity. A link’s power is determined by the amount of backlinks and the quality of the backlinks that are pointing page that the link is on.
Power is noted by UR (URL Rating) on Ahrefs and by PA on Moz.
If an article with 300 backlinks pointing to it then links to your site/page, you can pretty much guarantee that it’s a pretty powerful backlink.
A backlink that’s low on power but high on authority/relevance can still be a quality backlink. Just make sure you’re not getting only low power links, low authority links, or low relevance links.
Natural sites get a healthy mix of low/high for all three of these metrics – and so should you.
Traffic and Rankings
Two metrics that are worth mentioning are traffic and rankings.
If a linking page has either of these, it can be very beneficial to the link. That being said, they don’t seem to be quite as important as power, relevance, and authority.
A good example of a backlink that usually doesn’t have any traffic or rankings would be a PBN link… and we all know how much work PBN links can do for a site when used intelligently.
If you have the choice between two links with equal metrics, and one of them has traffic/rankings while the other doesn’t – take that one! But don’t write-off a backlink just because it’s low on these metrics.
Different Links for Different Jobs
Besides the idea of different types of links being useful due to the concept of link diversity, most also have unique purposes in the hands of a skilled SEO.
Broadly, you can categorize most links as either pillow links or pushing links. Pushing links are generally harder to get or more expensive than pillow links, but that does not mean pillow links are low quality backlinks.
Pillow links include links such as web 2.0s, citations, blog comments, social profiles, press releases, and so on. These links don’t usually provide the raw pushing power of other link types, but they are great for diversification and their own specific uses.
For example, citations are a very natural type of pillow link that builds trust as well as adding location relevance. These links won’t push you to the top positions, but they are still very important.
Pushing links are links such as niche edits, guest posts, authority links, and PBN links. These are the tools that do most of the pushing to the top of the Google SERPs. Each are slightly different and extremely useful.
For more a more detailed explanation of backlink types and their uses, check out our article on backlink diversity.
Anchor text, or the clickable text of the link itself, is another important component of backlinks which we’ve already discussed briefly in the relevance section.
In the past, SEOs overused keywords in their anchor text to jump straight to the top positions. Now, that will land you in some serious trouble.
You still want exact match anchors, but a link can still be a high-quality backlink if it has non-keyword anchors such as URL, branded, or generic variations.
Just like you need to diversify your backlink profile, you also need to diversify your anchor profile. A link with keyword anchors might do more pushing, but you can’t use only keyword anchors and expect to succeed in the modern era of SEO.
A contextual link is a link that exists within a paragraph of information. All of the links you see in this article with the orange text are contextual.
Contextual links are more sought after than non-contextual links because they help to build relevance. But like we discussed before, every link doesn’t need to be the most relevant link that’s ever existed.
Links such as sidebar links and footer links can still pass tons of juice if they are on authoritative, powerful pages.
You don’t want mostly footer and sidebar links as that would be very unnatural, but that doesn’t mean they are low-quality links.
Indexation and Crawlers
In general, you want your links to be on pages that are indexed by Google. You can check for indexation by using the “site:” search operator.
If you just got a guest post link from a new article, it might take some time for Google to index it (based on the size/authority of the linking site). You will want to make sure that all of your pushing links eventually get indexed.
Some types of pillow links might take forever to index or not index at all. We usually don’t worry too much about pillow links not indexing. There is evidence that shows that Google still knows about these links/pages even though they don’t display them in their visible index.
You have to remember that Ahrefs is an imperfect crawler and it takes serious time to crawl the entire internet. It might take Ahrefs a lot longer to add a link to its index than Google, and sometimes it won’t even add it at all. Remember that Google decides which links matter – not Ahrefs, Moz, or anyone else.
See our Ahrefs guide for more information on how we like to use this powerful tool.
Unless you are a veteran SEO that understands the risks involved, you probably don’t want to mess around with spammy links.
That being said, there is a lot of misunderstanding on this topic. Here are some different things that some SEOs consider spam:
Visual Outdated / Unstrustworthy Looking Sites – Google’s bots do not know what “trustworthy” looks like or what good design looks like. Disregard these factors when determining the quality of a backlink.
High Amounts of Outbound Links from the Linking Page – This can actually matter, however the number of outbound links a linking page can safely have without diminishing the value of your link is not known. Got a link on a page with 500 outbound links? Probably not too good.
Auto-Generated Links – Stay away from these unless you’re a black-hat pro. Getting tons of links with keyword rich anchors with slight variations in anchors/URLs/etc can be highly damaging to rankings and link profile.
Spun Content – Links from spun or extremely low content is not a good thing. You won’t always have problems, but it definitely increases the chances.
Think you’ve got some spammy links and you want to get rid of them? You might want to consider a disavow. However, use this as a last-case scenario and only if you are sure the links in questions are actually spam and that they are actually having a negative impact on your site.
White-Hat, Gray-Hat, Black-Hat
Contrary to what white-hat purists may scream at the top of their lungs from the moment they wake up every day, Google does not know the difference between a white-hat link and a black-hat link if you are following industry best-practices and safe link building techniques.
Of course there is more room for user error when building gray-hat and black-hat links, and the inexperienced or uninformed can land themselves in trouble in the form of penalties – algorithmic or manual.
But in the hands of a skilled SEO, that “hat” of a backlink has zero effect on its quality.
In a perfect world, better links would always be more expensive and vice-versa. In the real world, this isn’t so much the case.
While you can generally safely assume that dirt-cheap backlinks are too good to be true, it doesn’t always work the same in the other direction.
Higher prices does not always mean higher quality when you are buying links.
This is because link vendors do not always have control over the pricing for the site your link is placed on. Prices for guest posts, for example, are set by the site owners. You will have to make your own judgement as for if the link is worth it for you.