Backlinks Explained: What They Are & When to Worry

What is a backlink?

A backlink is simply a link from someone else's website to yours. That's it. If a local newspaper writes about your business and includes a link to your website in the article, that's a backlink. If a blogger reviews your product and links to your shop page, that's a backlink. If a spam directory lists your domain alongside ten thousand others, that's also a backlink — just not one you'd want.

The technical community has a dozen different names for them — inbound links, incoming links, external links — but they all mean the same thing: another website is pointing at yours.

Why Google cares about backlinks

When Google tries to decide which websites deserve to show up first in search results, it looks at hundreds of different signals. Backlinks are one of the most important ones.

The logic is straightforward. If lots of reputable websites link to yours, Google takes that as a sign that your site has something valuable to offer. It's like a recommendation system — the more credible recommendations you have, the more Google trusts you.

This is why a website with thousands of quality backlinks from news sites, industry publications, and trusted businesses tends to rank higher than a brand new site with no links at all. The links act as votes of confidence.

Not all backlinks are equal

Here's where it gets interesting. A single link from the BBC is worth more than a thousand links from random directories. Google doesn't just count links — it weighs them based on the quality and relevance of the linking site.

A few things that make a backlink valuable:

The linking site has authority. A link from a well-known, established website carries far more weight than a link from a site nobody has heard of. Google has its own way of measuring authority, and while it's not public, the general principle is obvious: links from bigger, more trusted sites matter more. The link is relevant. A link from a website in your industry is more valuable than one from a completely unrelated site. If you're a dentist and a dental industry publication links to you, that's a strong signal. If a random cooking blog links to you, it's less meaningful (though not necessarily harmful). The link is editorial. This means someone deliberately chose to link to you because your content was useful or relevant. Google values these "earned" links much more than links you placed yourself — like directory listings, forum signatures, or blog comments. The link is followed. Without getting too technical, there are two types of links: "follow" links (which pass ranking power) and "nofollow" links (which don't, or at least pass much less). Most normal links are follow links by default. Social media links and many comment sections use nofollow.

How your site gets backlinks

There are basically three ways backlinks appear in your profile:

You earned them. You published something useful — a guide, a tool, a piece of research, a strong opinion — and other people linked to it because it was genuinely worth referencing. This is the gold standard. These links happen naturally and they're exactly what Google wants to reward. Someone built them for you. An SEO agency, a freelancer, or even you personally went out and actively created links through guest posts, directory submissions, outreach campaigns, or other tactics. Some of this is perfectly fine. Some of it crosses into manipulative territory. The line is blurry, which is partly why link building is such a controversial topic in SEO. They appeared on their own — from spam. Spam sites, scrapers, link farms, and automated tools generate millions of links every day, pointing at random websites. If your site has been online for any length of time, you almost certainly have some of these. You didn't ask for them. You can't stop them. They just show up.

When backlinks become a problem

For most website owners, backlinks are something you never need to think about. They accumulate naturally, Google handles the spam ones automatically, and your rankings take care of themselves.

But there are situations where backlinks stop being a quiet background process and become an active problem:

You hired someone who built bad links

This is the most common scenario. An SEO agency promised to improve your rankings and delivered by building hundreds of links from low-quality directories, private blog networks, and guest post farms. At the time, your rankings might have gone up. But those links are now a liability — either actively hurting you or waiting to hurt you when Google's next algorithm update catches up.

You're being targeted by a competitor

It's called negative SEO, and while it's less common than SEO forums would have you believe, it does happen. A competitor points thousands of spam links at your site, hoping Google will penalise you for it. If you notice a sudden, unexplained spike in low-quality backlinks, this might be the cause.

Your site received a Google penalty

If Google issues a manual action against your site for "unnatural inbound links," your backlinks have officially become a problem that needs solving. Manual actions can tank your traffic and won't resolve themselves — you need to actively clean up your link profile and request reconsideration.

Your backlink profile is mostly spam

Some websites, particularly in competitive or spam-heavy niches, end up with more toxic backlinks than legitimate ones. When the ratio tips too far toward spam, it can drag your rankings down even without a formal penalty.

What "toxic" actually means

A toxic backlink is a link from a source that Google considers low-quality, manipulative, or unnatural. The word "toxic" gets thrown around a lot in SEO, sometimes for dramatic effect, so let's be specific about what it means:

Spam sites. Websites that exist only to host links. No real content, no real visitors, no purpose other than manipulating search rankings. Link farms. Networks of sites that all link to each other (and to paying customers) to artificially inflate link counts. They're the SEO equivalent of fake reviews. Private blog networks (PBNs). Fake blogs built on expired domains, designed to look independent but secretly controlled by one operator who sells link placements. Hacked sites. Legitimate websites that have been compromised and are now hosting spam links without the owner's knowledge. Automated junk. Links generated by bots and scripts that create profiles, comments, and directory listings at scale. These are the background radiation of the internet — low-level spam that never stops.

What you can actually do about bad backlinks

If you've read this far and you're worried about your backlinks, here's the practical advice:

Check your backlink profile. Use a backlink audit tool to see what's linking to you. You might be pleasantly surprised — most small business websites have mostly clean profiles with a sprinkling of spam that Google handles automatically. Don't panic over a few spam links. Every website has some. A handful of junk directory links isn't going to hurt you. Google expects them and ignores them. Act if you see a pattern. If your audit reveals hundreds of links from obviously spammy sites, or if you recognise the footprint of a dodgy SEO campaign, it's worth cleaning up. Build a disavow file listing the toxic domains and upload it to Google Search Console. Monitor regularly. Your backlink profile isn't static. New links appear constantly. A quarterly check is enough for most sites. Monthly is better if you're in a competitive niche or have a history of link problems.

Check your backlinks for free

If you want to see what's in your backlink profile right now, our free backlink checker shows you the top links for any domain — no signup needed. And if you find something concerning, our step-by-step guide to finding and removing toxic backlinks walks you through exactly what to do.

The thing most people get wrong

The biggest mistake people make with backlinks is one of two extremes: either they ignore them completely and hope for the best, or they obsess over every single one and try to micromanage their link profile.

The right approach is somewhere in the middle. Know what's in your backlink profile. Understand the basics of what makes a link good or bad. Clean up the obvious problems. And then focus your energy on the things that actually build your business — creating useful content, serving your customers well, and earning the kind of links that no algorithm update can take away.