What Is a Backlink Audit and How to Do One Free

The short version: a backlink audit is a full review of every link pointing to your site so you can spot the ones helping you and the ones quietly harming you. You can do a real one for free using Google Search Console plus a free-tier tool, you just need to know what to look for and roughly 2 to 3 hours per audit. The contrarian bit nobody tells you: most sites don't need a disavow file, they need better content and more patience, and reaching for disavow first is often a waste of your afternoon.

What a backlink audit is

A backlink audit is the process of pulling together every link pointing at your domain, then sorting them by quality, relevance and risk. You're looking for three things: links that are helping you rank, links that are doing nothing at all, and links that could be actively hurting you. That third group gets all the attention online because it's dramatic, but in my experience the second group, the dead weight, is usually bigger and more worth your time.

Most people confuse a backlink audit with a backlink checker run. They're not the same thing. A checker gives you a list. An audit is what you do with that list: categorising, judging, deciding, and sometimes acting.

Why bother, when Google says it mostly ignores bad links anyway

Google has said for years that it largely discounts spammy links rather than penalising you for them. That's true, mostly. But "mostly" is doing a lot of work in that sentence. There are still real situations where a backlink audit earns its keep:

• You've had a sudden, unexplained ranking drop and want to rule out a link-based manual action
• You inherited a site (bought it, took over a client, merged brands) and have no idea what's pointing at it
• You ran a link-building campaign years ago through an agency and never checked what they built
• You're about to invest serious money in new SEO and want a clean baseline first

If none of those apply to you, you can probably skip the deep audit and just do a light check twice a year. Don't let anyone tell you this is a monthly must-do for every small site. It isn't.

The free step-by-step process

Step 1: pull your full backlink list

Start in Google Search Console under Links, which shows links Google itself has indexed, free, straight from the source. Then add a second source because Search Console's data is incomplete. Ahrefs' free Webmaster Tools tier, once you verify your site, gives you backlink data Google Search Console won't show. If you want the full picture of what's out there, it's worth reading how Ahrefs' free tools work before you rely on them for an audit. For the wider context on how to see the full history of backlinks your site has earned, that's worth a separate read too, because audits are stronger when you can see trends over time, not just a snapshot.

Step 2: get a real number

Before you judge quality, know your scale. If you're not sure how big the list even is, start with a simple approach to counting the total backlinks pointing to your site across both tools, then reconcile the two lists into one spreadsheet. Export both as CSV, combine them, remove duplicate URLs, and you've got your master list.

Step 3: sort by referring domain, not raw link count

This is where most free audits go wrong. People look at "1,200 backlinks" and panic or celebrate. What matters is referring domains, meaning how many separate websites link to you. A site with 50 links from one forum has 1 referring domain and almost no value. A site with 50 links from 50 different blogs has real authority behind it. Sort your spreadsheet by domain and count uniques first.

Step 4: score each domain on four things

• Relevance - does this site have anything to do with your industry or audience?
• Traffic - does it look like a real site with real visitors, or a dead directory?
• Anchor text - is it natural phrasing or obviously stuffed with exact-match keywords?
• Placement - is it in the body content or buried in a footer/sidebar link farm?

Flag anything that fails two or more of these as a candidate for closer inspection, not automatic removal.

Step 5: separate "harmful" from "useless"

This is the step that saves you from wasting hours on disavow work you don't need. A link from a long-dead blog in a different language that happens to mention your brand name is useless, not harmful. It does nothing either way. A link from a known private blog network with 200 outbound links on one page, exact-match anchor text, and zero real traffic is a genuine candidate for review. If you're unsure where the line sits, there's a dedicated breakdown on how to determine which backlinks are hurting your site, worth reading before you touch the disavow tool, because disavow is a blunt instrument and Google treats it as a serious signal.

A worked example

Say you run a small accountancy practice site with 340 backlinks from Search Console and Ahrefs combined. After deduplicating, that's 190 unique referring domains. You sort them and find:

• 22 domains are local business directories (Yell, Thomson Local, local chamber of commerce) - fine, low value but harmless
• 140 domains are genuine, relevant mentions: local news coverage, a guest post you wrote for an industry body, client testimonial pages linking back - these are your real assets
• 18 domains are old web directories from 2014 that no longer get crawled or indexed - useless, ignore them
• 10 domains look like a link scheme: identical footer placement, exact-match anchor "best accountant London", no real content on the linking pages, all registered within the same month

Out of 190 domains, only 10 warrant real concern, that's about 5%. For most sites that's roughly the proportion you'll find: a small, specific cluster worth a closer look, surrounded by a much bigger pile of stuff that's neither good nor bad, it's just noise. That's the uncomfortable truth most backlink audit guides skip: the dramatic "toxic links are killing your rankings" framing sells tools and services, but for the average small business site, the bigger problem is almost always too few quality links, not too many bad ones.

What to do with the bad ones

Before disavowing anything, try to get the link removed manually. Find contact details for the site, send a polite request, wait two weeks. Only once you've exhausted that, or the site is clearly unreachable or malicious, should you build a disavow file in Google Search Console. Keep it short. A disavow file with 10 domains that need it does far more good than one with 200 domains you weren't sure about, because every entry is treated by Google as a serious instruction, not a suggestion.

How this fits into your wider SEO picture

A backlink audit is one piece, not the whole puzzle. If you've never run a full technical check, pair this with a free SEO audit covering the rest of your site so you're not fixing links while ignoring broken pages, slow load times or thin content, all of which matter more day to day than a handful of dodgy directory links from 2015.

How often to do this

Twice a year for most small and medium sites. Quarterly if you're actively building links or running digital PR campaigns. Immediately if you see a sudden traffic drop with no obvious cause and you've ruled out a Google algorithm update first, because 9 times out of 10 that's the actual culprit, not your backlink profile.

Frequently asked questions

Is a backlink audit worth doing for a small business website?

Yes, but only once or twice a year unless you're actively building links. For most small sites the bigger win is building a handful of relevant new links rather than chasing down old toxic ones that are quietly doing nothing.

Can I do a full backlink audit without paying for a tool?

Yes. Google Search Console gives you a free, direct-from-Google list, and Ahrefs' free Webmaster Tools tier adds data Search Console misses. Combining both gives you a workable, free master list for most small and mid-sized sites.

How do I know if a backlink is hurting me rather than just useless?

Look at relevance, anchor text pattern, placement and whether the linking page has any real traffic or content. A single odd link rarely hurts you. A cluster of identical, irrelevant, exact-match links pointing from clearly low-quality or spammy sites is the pattern worth reviewing closely.

Should I use Google's disavow tool after my audit?

Only for links you've tried and failed to get removed manually, and only if they fit a genuine spam pattern. Most sites don't need a disavow file at all, and an overly long one can do more harm than the links it's meant to fix.