Should You Nofollow All External Links in Your Blog Posts?

The idea of nofollowing all the external links on your site tends to come from two different places. In one case, it comes from a faulty understanding of “link juice” and how that whole system works. In the other, it comes from a sort of overkill “better safe than sorry” perspective.

Should you nofollow every external link on your site? No. You can, if you want. But it won’t be effective and might get you flagged as a site trying to abuse an old spam technique.

Link Juice and PageRank Sculpting

Link juice is the visualization of the value of a link passing into and out of a site through holes, represented by links.

The thinking went like this. Your site has link juice coming in from every site that’s linking to you - it also is losing link juice from every link you point out to another site. Before the nofollow attribute was introduced in 2005 - to fight comment spam - you basically had to work with it. Once nofollow hit, you had a new strategy of manipulating this link juice.

Imagine if you had this value flowing into your site. But you clogged the holes. All of the links pointing out to other sites would be nofollowed. But the internal links would feed back upon themselves, which makes a system with input but no output.

You would think that this is a great technique for retaining value and growing your site. You don’t lose anything, you’re gaining from incoming links, and you grow faster than if you were linking out with followed links.

A more advanced version of this visualization means numbers. Your page, say, is worth 6 PageRank. You link out to three websites; two others and one of your own, and each of them gets 2 of your 6 PageRank, leaving your page with nothing. Well - not nothing; 2 of that PageRank is feeding back into your site somewhere else.

You decide that 2 is not enough, so you nofollow one of the links to an external site - it means the 6 PageRank is split in two, instead of in three, so each link is now worth 3 PageRank. Your page still loses 6. But instead of 2 cycling back in, 3 is.

The idea was, if you nofollowed every external link, all PageRank from your site cycles back into your site via internal links.

This all worked for a while. But Google very quickly found sites using nofollow to sculpt their PageRank and subvert the value of links throughout the web. A web without helpful links undermines the basic foundation of Google’s algorithm, so they couldn’t let it stand. They changed how PageRank mixes with nofollowed links. It no longer works. That was already settled back in 2009.

Now, let’s take the numerical experiment. You have a page worth a nebulous concept of 6, and you have three links pointing out, and each of the links is passing along 2 PageRank, ignoring the variables about relative site value and relevance of content.

You nofollow the two external links, so your 6 PageRank flows back into your site through the one internal link. You measure - though no tool for this measurement exists - and find that the link is still just passing 2 link juice.

Modern Google link juice watching takes the total value of the page and divides it up amongst the links on the page, regardless of what position or attributes those links have. If you nofollow a link, no link juice flows through that link. But the link still exists - it still counts for dividing up PageRank, and still decreases the amount of PageRank that flows out through each other link. PageRank sculpting died in 2009.

Well, you can do that, and probably should; it’s why when I use “www.example.com” on my sites, I explicitly don’t make it a hyperlink. Google could be savvy enough to find that it’s an example link and not something I mean to include in the value calculation. But they might not, and that’s not a danger I want to take.

What if you go the other way and just remove all external links? You can. But chances are it’s more likely to hurt you than help you. Three reasons why:

1. It’s unnatural link sculpting. Google has an absolutely massive sample size - basically the whole internet - so they know what a natural link profile is likely to look like, and they know what kind of actions people might take to try to game the system. Even if your actions don’t match a specific negative profile, they can see that you’re outside the norm, take a closer look, and determine that you should be penalized for it.
2. External links are known to be valuable to the linking site. This doesn’t mean you can just throw a dozen links on every page and have value roll in, but it IS an implicit hint from Google that linking out is better than not doing so.
3. Users will feel less value on the site. If I’m reading a page and someone states a fact, I’d like to see a source for that fact. If someone is reporting news, I want to know the source for that news. Links are huge for informational purposes, and even if I don’t explicitly notice that they’re gone, I’ll still feel a lack of options when reading a site with no external links.

The fact is, you need external links, and you’ll have to use them. So how and when should you use nofollow on your blog posts if you want to be in top compliance?

A Critical Update: Nofollow Is Now Just a Hint

Before talking about the rules, there’s something important that has fundamentally changed the nofollow conversation. As of March 1, 2020, Google officially changed how it treats nofollow links. Rather than a hard directive to ignore a link entirely, nofollow became what Google calls a “hint” - meaning Google may crawl, index, and might pass some value through a nofollowed link at its own discretion.

An AuthorityHacker survey found that 89.1% of SEO pros believe nofollow links change rankings, and 46.9% of link builders actively go after nofollow links as part of their strategy. Moz’s analysis found a 0.32 correlation between nofollow links and rankings - nearly identical to the 0.34 correlation for dofollow external domains; it’s a remarkably small gap.

Further analysis of 200+ nofollow links across client websites found that 22% drove measurable referral traffic, 41% of nofollow links in blog posts caused secondary backlinks, and pages with 5 or more quality nofollow mentions earned 23% more organic backlinks over time. Most pages ranking on Google’s first page average 20-40% of their total backlinks being nofollow.

What does this mean practically? It means nofollow is no longer the hard off-switch it once was - it’s still a helpful signal to send Google, and you should still use it appropriately - but don’t think of a nofollowed link as valueless, because Google increasingly doesn’t either.

Properly Using NoFollow on External Links

So, nofollow is still a useful attribute to add to links. But when and how should you use it? You don’t want to nofollow links indiscriminately, because it doesn’t help you and cuts back on your site value signals. You also don’t want to leave in value-passing links to spam sites, because then you’re sending positive signals toward a black hole.

Rule #1: Think of a link as a vote of confidence. Links pass value by default, unless you remove that value. And given the 2020 change - even nofollowed links may carry some implied weight - so be intentional about the direction your links point.

Ignoring all other rules, you can use your best judgment. If you think the site you’re linking to is worth receiving your vote, the link can be followed. If you don’t think the site is worthy, nofollow the link. A few nofollowed links isn’t a bad thing. I’ve seen sites that deliberately nofollow links to their competitors, just out of a minor bit of spite. There’s nothing wrong with that as far as Google is concerned, as long as you don’t over-do it with an overly large definition of competitor.

So what kinds of links should you nofollow, according to Google and according to SEO pros and their experiments?

Links that were paid for. Any sort of link that you received payment for should be nofollowed - this includes those who pay to take up a guest contributor slot on your site - this includes those who give you a product to review in exchange for a link to their product pages - this includes those who try to bribe you with a direct contribution or a buyout - this even includes “payments” of other links, if this direct form of collusion is offered. Google also introduced the rel=”sponsored” attribute in 2019 specifically for paid and affiliate links, which is now the preferred tag for those use cases.

Links that stem from a commercial relationship. This one is a large catch-all to cover the above. A commercial relationship can include things beyond paying for a post. Links from business partners might qualify. Links from other sponsors of an event you run. Anything where there’s a potentially reciprocal profit going on could be better nofollowed - or tagged as sponsored - than not.

Of course, in reality, sites want to use links to benefit their sponsors and partners - it’s fine to let a few of these through. The problem comes if you’re arranging these sponsorships in exchange for links, or you’re running some link scheme with product purchasing as an incentive. There are a number of different variations to these scenarios, so just ask yourself if Google or an impartial third party would see you as accepting bribes or payment in exchange for link value. If so, nofollow or sponsor-tag the links to be on the safe side.

Links generated by users. Any time a person who is not you or another page admin is able to add a link to your site, you should nofollow that link. Unless you vet every link coming through your page, you don’t want someone with no oversight able to create a vote in your name. Google also introduced the rel=”ugc” (User Generated Content) attribute in 2019 specifically for this scenario, and it’s now the recommended tag for forum posts, comment sections, and similar user-submitted links.

The most common instances of this are web forums and blog comment sections. Web forums tend to be blanket nofollowed to try to stay away from spam, though spambots will still happily spam a forum open to guest posting or cheap registration. Blog comments also usually should be nofollowed or UGC-tagged, as it discourages the worst of the spam.

That said, if you’re willing to personally vet and approve any link that comes in through your comments, you can leave them followed. You just have to then make sure that you stay on top of this moderation and ensure that the links you’re approving are worthwhile. Google won’t penalize you for a comments system that includes followed links.

If you’re not willing to handle the moderation yourself, then you’ll have to make sure those kinds of submissions are automatically nofollowed or UGC-tagged. You can always include a link to the same page later as a source if you like it enough.

Links to sites that are low quality. The big one. For any website you aren’t sure of the quality of, or that you’re pretty sure is low quality, go ahead and nofollow the link. Always remember that your link is a way of passing a vote of confidence. If you wouldn’t want to introduce this website to your grandparents at Thanksgiving, you shouldn’t give it your endorsement - this includes spam sites, sites with user content you might not want to vouch for, and brand new sites in your niche that you might not know are helpful yet.

Links that are irrelevant. If I was going to link to a shoe store to give you an example of a store page, I’d probably nofollow that link. The reasoning here is a little different though. See, when a link comes into your site from an irrelevant page, it has next to no value. Irrelevant links can even be harmful. Google might believe that they’re coming from purchased link programs or private blog networks.

Rather than make the site owner work later asking me to remove or nofollow a link they deem valueless to their own SEO, I just nofollow them by default - this way they don’t have to worry about the links, and I can still use them to give you an example without having to go through a tedious process of screenshotting and formatting images to use instead of a link.

Links to system pages that the average user doesn’t need to find through search. The normal user might be interested to see your privacy policy or your About page or some other system page. But they don’t necessarily need to rank prominently in web search. You can nofollow links pointing to them if you want to limit how much crawl priority and link equity flows in that direction. But still keep the pages accessible and indexable for compliance purposes.

If you follow these rules, you should be able to use nofollow appropriately the majority of the time. You might nofollow a few extra links or leave in a few borderline ones. But that’s natural. A few links won’t hurt you - it’s only when you’re abusing them one way or another - or treating nofollow as a foolproof wall - that you can find a penalty or a lost opportunity waiting.