What Are Backlinks and How Do They Work

The short version: a backlink is simply a link from another website to yours, and Google reads each one as a small vote of trust, but not all votes count the same. One link from a site Google trusts can outweigh five hundred from sites it doesn't, which is the bit most explainers skip over in favour of telling you to "just get more links."

What a backlink is, in plain English

A backlink is a hyperlink on someone else's website that points back to yours. If the BBC writes a piece about small business grants and links to your funding guide, that's a backlink. If a supplier lists you on their partners page with a link to your homepage, that's a backlink too. It sounds small, and on its own it is, but multiply it across a few hundred sites and it becomes one of the biggest ranking signals Google uses.

They're also called inbound links or incoming links. Same thing, three names, because SEO people love picking a favourite term and arguing about it.

How Google uses backlinks (a short history that matters)

This isn't ancient trivia, it explains why some links help you and others do nothing. Google's founders built the search engine around a system called PageRank, patented at Stanford in the late 1990s. The idea was simple: treat a link like an academic citation. If lots of respected papers cite your paper, your paper is probably worth reading. Google applied the same logic to the web, you can read the original concept on Wikipedia's PageRank page if you want the full mechanics.

What matters for you today is this: Google still counts links as trust signals, but it's got far better at judging the quality of the site doing the linking, the relevance of the page, and whether the link looks earned or bought. A link from a page about wedding cakes to your accountancy site tells Google very little. A link from an accountancy trade body to your accountancy site tells Google a lot. This is the core of why backlinks are important in the first place, they're one of the clearest outside signals Google has that other humans and other websites vouch for you.

The metric everyone chases that Google doesn't use

Here's the bit that tends to get glossed over. Domain Authority, the score you see in Moz, and Domain Rating, the version in Ahrefs, are not Google metrics. They're invented by those two companies, calculated with their own formulas, and Google has confirmed more than once that neither one factors into rankings at all. I've sat across the table from business owners who were devastated their "DA" was 12 while a competitor sat at 45, convinced that was the whole reason they weren't ranking. Sometimes it correlates loosely with strength, because sites with lots of good links tend to score higher on both. But I've seen a site with a DA of 8 outrank a site with a DA of 40 for the exact keyword that mattered, because the smaller site had three links from relevant, trusted pages and the bigger one had three hundred links from directories nobody visits. Use these scores as a rough compass, not as the actual scoreboard, because they aren't the one Google is keeping.

The different types of backlinks and what they're worth

Dofollow versus nofollow

By default, a link passes on some of its trust to the page it points at. That's a dofollow link. Add a small piece of code, rel="nofollow", and the site owner is telling Google "I'm linking to this but I'm not vouching for it." Most comments sections, forum signatures, and paid links carry a nofollow tag. Nofollow links can still bring you real traffic and real visibility, they just don't pass the same ranking signal, so a site full of nofollow links won't move your rankings much even if the numbers look impressive.

Editorial links versus built links

An editorial link is one a writer or editor added because your content was the best source, no request, no exchange, no favour. A built link is one you asked for, pitched for, or created, a guest post, a directory listing, a partner mention. Editorial links carry the most weight because they're the hardest to fake. Built links still work and still make up the bulk of most link profiles, but the quality gap between a strong built link and a weak one is enormous.

Anchor text

Anchor text is the clickable words in the link. A link that says "click here" tells Google almost nothing about your page. A link that says "affordable AI consultant for small business" tells Google exactly what the destination page is about. Over-optimising this, stuffing exact-match keywords into every anchor, is one of the fastest ways to trip Google's spam filters, so a natural mix of branded, generic, and keyword anchors is what a healthy profile looks like.

A real example: what one good link did for a client

A few years back I worked with a small B2B software client selling scheduling tools to trades businesses. They'd written a useful piece on apprenticeship shortages in the trades, backed by real survey data they'd collected themselves. It sat quietly on page four of Google for their target keyword for months. Then a journalist writing for a national trade publication found it, quoted the stats, and linked back to the page. One link, from one relevant, trusted domain.

Within about six weeks that page moved from position 34 to position 6. No other changes were made to the page in that window, no fresh content, no technical fixes. That one link, on a site Google already trusted in that exact industry, did more than the previous four months of on-page tweaks combined. It's the clearest proof I've seen first-hand that relevance and trust beat volume every time.

How many backlinks do you need

There's no set number, and anyone who gives you one is guessing. I've seen pages rank in competitive spaces with under ten backlinks, because those ten were strong and relevant. I've also seen pages with over a thousand backlinks sit on page three, because most of them came from low-quality directories or spun content sites built purely to sell links. What I look at instead is the mix: how many unique referring domains, how many of those domains would a normal person recognise, and how many links point at money pages versus blog posts.

If you want to see where you stand right now, there's a straightforward way to check this yourself rather than guessing, laid out in this guide to finding out how many backlinks your website has. Most free tools will give you a rough count and let you see your top linking domains, which is enough to start spotting patterns.

Checking and tracking your backlinks (step by step)

Here's the version I walk clients through:

• Set up Google Search Console if you haven't already, it's free and shows you real linking domains Google has crawled, not an estimate.
• Go to Links in the left menu, then look at "Top linking sites" to see who's pointing at you already.
• Sort by the pages getting the most links, this tells you what content is naturally attracting attention so you can build more like it.
• Check for spammy patterns, dozens of links from the same low-quality domain, or gambling and casino sites you've never heard of, which sometimes appear through negative SEO or scraped content.
• Record your total referring domains once a month in a simple spreadsheet, not just the raw link count, since one domain can carry fifty internal links that all count as one vote of trust, not fifty.

If you'd rather not pay for Ahrefs or Semrush every month just to watch a number move, there's a workable way to keep an eye on this over time without a paid subscription, covered in this guide to tracking backlinks without a paid tool. It won't give you the depth a paid tool does, but for most small businesses it's more than enough to spot trends.

How to earn backlinks

The uncomfortable truth is that most link building advice is about tactics, and most tactics stop working once too many people copy them. Guest posting worked brilliantly around 2015, then everyone did it badly, and Google's spam team started devaluing thin guest posts en masse. What still works consistently, year after year, is being the source someone else needs. Original data, a useful free tool, a well-argued opinion piece that a journalist can quote, a resource so complete that people link to it instead of rewriting it themselves.

If you want a fuller walkthrough of tactics that hold up rather than the ones that used to work, this guide to building backlinks the right way covers the specifics. And if budget is tight, which for most small businesses it is, there's a list of free ways to earn links in where you can get backlinks for free, including things like HARO-style journalist requests, supplier and partner pages, and local business directories that get traffic rather than sitting unread.

What I'd steer you away from, plainly, is buying links in bulk from marketplaces promising "50 high DA links for £99." Google's webspam team has spent over a decade getting better at spotting exactly this pattern, and I've seen sites lose 70% of their organic traffic overnight after a manual action for unnatural links. It's not worth the risk for a shortcut that barely moves the needle anyway.

Why this still matters more than most people think

Content quality and technical SEO get most of the attention in 2026 because they're easier to control and easier to sell as a service. But backlinks remain one of the strongest signals Google has for telling two similarly optimised pages apart. I've watched two clients in the same industry, with near identical on-page SEO, split by a wide ranking gap purely because one had spent two years building relationships that turned into links, and the other hadn't. For a deeper look at why this signal has stayed this powerful for over two decades, it's worth reading why backlinks matter so much for your website's ranking, which goes into the ranking mechanics in more depth than I can cover here.

If you want to check a domain before you pitch or buy from it, my free backlink checker pulls the live backlink profile for you.

If you write on this topic, see Websites That Accept Guest Posts in 2026 (Real Sites, Real Rates, No Fluff).

A closely related guide: What does a good backlink example look like, and a bad one.

Related: guest post marketplace.

Ahrefs is the name most people know for this. Here are the Ahrefs alternatives, sorted by the feature you'd miss.

Frequently asked questions

What counts as a good backlink?

A good backlink comes from a relevant, trusted site that a real audience reads, uses natural anchor text, and is placed within genuine content rather than a footer or sidebar built purely for links.

Do nofollow links help SEO at all?

They don't pass the same ranking signal as dofollow links, but they still bring real traffic, build brand visibility, and sit naturally within a healthy link profile, so they're worth having even though they won't directly lift your rankings.

How many backlinks does a website need to rank on page one?

There's no fixed number, pages have ranked with fewer than ten strong links and failed to rank with over a thousand weak ones, so the quality and relevance of the linking domains matters far more than the raw count.

Can buying backlinks get my website penalised?

Yes, Google's webspam systems are specifically built to detect bulk-bought and unnatural link patterns, and a manual action for this can cause a sharp, sudden drop in organic traffic that can take months to recover from.