What are backlinks, and how do you check yours free?

What are backlinks?

Backlinks are links on other websites that point to a page on your website. If a local newspaper writes about your bakery and links the words “the bakery on Main Street” to your homepage, that link is a backlink to you. SEO people also call them inbound links, incoming links or external links, and the websites they come from are your referring domains.

Two things are easy to mix up here. A link from one page of your site to another of your own pages is an internal link, not a backlink; it matters too, but you control it completely (our internal linking feature is about those). And a link from your site to someone else's is an outbound link: it is their backlink, not yours.

Backlinks matter for two plain reasons. People click them, so they send visitors who were already reading about your topic. And search engines read them: a link is one website telling its readers that another page is worth their time. That is the idea behind Google's PageRank and behind every third-party authority score, from Moz Domain Authority to Ahrefs Domain Rating (see what is domain authority for how those scores differ).

What are the parts of a backlink?

Every backlink has four parts: the page it sits on, the address it points to, the clickable words or image, and an optional rel attribute that tells search engines how to treat it. In HTML, a backlink to your site looks like this:

<a href="https://yoursite.com/pricing" rel="nofollow">affordable SEO software</a>

• The linking page (source). The page on the other site where the link sits. Its topic, its readers and whether search engines index it all decide how much the link is worth.
• The target URL. The page on your site the link points to. Links to a page that now returns a 404 error help no one, which is why broken pages with backlinks are worth redirecting.
• The anchor text. The clickable words, here “affordable SEO software”. Google's link best practices say good anchor text is descriptive, reasonably concise and relevant to both pages, and that for an image link Google uses the image's alt text as the anchor text.
• The rel attribute. Optional. Values such as nofollow, sponsored and ugc qualify the link; a link with none of them is what SEO people call a “dofollow” or followed link.

Google also says it can generally follow a link only when it is a real <a> element with an href attribute. A “link” built from a script click handler may work for visitors and still be invisible to Google as a link.

How does Google use backlinks?

Google uses backlinks in two ways: to discover pages it has not seen yet, and as one signal, among many, of what a page is about and how relevant it is. Both come straight from Google's own documentation.

• Discovery. Google's SEO Starter Guide says the vast majority of new pages Google finds every day are found through links. A new page that nothing links to is harder for Google to find, which is why our guide to how search engines work starts with crawling.
• Relevance. Google's link best practices say it uses links as a signal when determining the relevancy of pages, and its guide to ranking systems lists link analysis systems and PageRank, which understand how pages link to each other, among its core systems.
• One signal, not the whole story. The same Starter Guide lists PageRank under things not to focus on too much. In Google's words: “We have many ranking signals, and PageRank is just one of those.”

So backlinks are real, and they are not magic. A page with excellent links and a poor answer to the search will still struggle, and a page with few links can rank for a specific question it answers better than anyone else. Our guide on how to rank on Google puts links in their place, as step eight of nine.

What is the difference between dofollow and nofollow links?

A nofollow link carries rel="nofollow" and asks Google not to associate the linking site with the target or crawl it from that link; a “dofollow” link is simply a link with no such value, so Google can count it normally. There is no rel="dofollow" attribute; the word is SEO shorthand. Google added two more specific values in 2019, and its page on qualifying outbound links defines all three:

Three details from Google's documentation are worth knowing:

• They are hints. Google's 2019 announcement said all the link attributes are treated as hints about which links to consider or exclude. Google says these links will generally not be followed, but the target can still be found another way, for example through a sitemap or a link from another site.
• You can combine them. rel="ugc nofollow" or rel="sponsored nofollow" are both valid. Google also said there is no need to change nofollow links you already have.
• Nofollow is not an insult. Google's link best practices tell site owners to use nofollow only for sources they do not trust, not on every external link. Plenty of reputable sites nofollow comment links or all user-submitted links by default.

Are nofollow backlinks worthless, then? No. They still send visitors, they make your brand visible where your audience reads, and because they are hints, Google may still consider them. They are just not something to build a ranking plan on.

What makes a good backlink?

A good backlink is one an author chose to give you, on a relevant page that real people read, in words that describe your page honestly. No public formula scores links, and no tool can read Google's mind, but the qualities below follow from what Google says it rewards and what it calls spam.

1. It is editorial

   The person who wrote the page decided your page was worth citing. That is the opposite of what Google's spam policies describe: links that were paid for, swapped or created by the site owner primarily to manipulate rankings.

2. It is relevant

   A link from a respected page about the same subject makes sense to readers and to search engines. A link from an unrelated site may lift a third-party score while doing little else.

3. Real people see it

   A link in the body of a page that gets read and clicked is worth more to you than one buried in a footer, a sitewide blogroll or a page nobody visits. If you would be glad of the link even if search engines did not exist, it is probably a good one.

4. The anchor text is natural

   Your brand name, the page title or a plain description are normal. A profile where most links use the exact keyword you want to rank for looks engineered, and Google's spam policies name optimized anchor text in paid articles and forum signatures as link spam.

5. It comes from a new domain

   The tenth link from a site you already have a link from adds less than a first link from a site that has never mentioned you. That is why backlink tools report referring domains alongside raw backlink counts: one site with a sitewide footer link can produce thousands of backlinks.

6. It points to a live page

   A link to a page that now returns a 404 loses its value for visitors. Redirect the old address to the closest live page with a 301, and the link is useful again.

Which backlinks should you avoid?

Avoid any link that exists mainly to manipulate rankings: Google's spam policies call this link spam, and they list the common forms by name. Google's spam policies give these examples:

• Buying or selling links for ranking, including paying in money, goods or services, or sending someone a free product in exchange for a write-up with a link.
• Excessive link exchanges, such as “link to me and I'll link to you”, or partner pages made only to cross-link.
• Automated programs or services that create links to your site.
• Requiring a link in a contract or terms of service without letting the other site qualify it.
• Text ads and advertorials that pass ranking credit, including paid guest posts and press releases with optimized links.
• Low-quality directory and bookmark links, keyword-rich or hidden links in widgets spread across many sites, and links spread through footers or templates.
• Forum comments with optimized links in the post or signature.

Paying for visibility is not the problem; hiding it is. Google says paid links are a normal part of advertising and sponsorship online, and do not break its policies when they carry rel="sponsored" or rel="nofollow". Sponsor an event, advertise in a newsletter, list your business in a directory your customers actually use: just make sure any paid link is qualified.

What happens to spam links? Google's December 2022 link spam update said it uses SpamBrain, one of its spam detection systems, to neutralize the impact of unnatural links, and that any credit those links passed is lost. Separately, the spam policies say violations can lead to a manual action, reviewed by a person. In practice that means bought links are, at best, money spent on nothing.

How do you check your backlinks for free?

To check your own backlinks free, open the Links report in Google Search Console; to check any website's backlinks, including a competitor's, use a free backlink checker such as MrKeyword's. No source sees every link, so using two is normal. Here are the free options:

For Google's own view of your site, here is how to read the Links report, step by step:

1. Open the Links report

   In Search Console, pick your property and choose Links in the left menu. If you have not verified your site yet, that comes first; it is free.

2. Start with Top linking sites

   This is your list of referring domains. Google's Links report help says data is grouped by root domain, so subdomains are combined. Click a site to see which of your pages it links to.

3. Check Top linked pages

   These are the pages other sites link to most. Any page here that now returns an error is a quick win: redirect it, or fix it, so the links count again. A broken link checker will confirm which addresses fail.

4. Read Top linking text

   The words other sites use for you. Mostly your brand name and plain descriptions is normal. A long list of exact-match keyword anchors you do not recognise is worth a closer look.

5. Export for a fuller list

   Use the export button and choose Latest links or More sample links. Google says exports can include up to 100,000 rows, while the tables on screen stop at 1,000. Remember it is still a sample.

Our guide to backlinks in Google Search Console goes further: how Google counts and groups the links, what the sample and row limits leave out, and how to compare two exports to find lost links.

Search Console only covers sites you own. To see who links to a competitor, enter their domain in the free backlink checker; to compare overall link strength across several sites at once, use the free domain authority checker.

How do you get backlinks the right way?

You get good backlinks by publishing something other people need to cite, and then making sure the people who would cite it know it exists. Google's SEO Starter Guide says that effectively promoting new content leads to faster discovery by people interested in the same subject; it also warns that you can overdo promotion. The tactics that hold up:

• Original facts. Your own data, prices, test results or a count nobody else has made gives writers something to quote, and the link comes with the quote.
• Useful tools and reference pages. A calculator, a checklist or a clear explanation that beats what already ranks gets linked from forums, newsletters and other guides over time.
• Unlinked mentions. Sites that already name your brand without linking are the easiest ask there is: a short, polite note usually does it.
• Broken backlinks. Old pages of yours that other sites still link to, but that now return 404, should be 301-redirected to the closest live page.
• The sites your competitors earned. A site that links to three of your competitors writes about your topic, and may be glad of a better resource.
• Real-world relationships. Suppliers, partners, local organisations and industry associations often list the businesses they work with.

Our guide on how to increase domain authority covers each of these in more depth, with what to say and what to skip. And do not neglect the links you control: a new page that your own related pages link to gets found faster, and our post on orphan pages shows how to find pages nothing links to.

Should you disavow bad backlinks?

Usually not: Google says most sites never need the disavow tool, because it can assess which links to trust without help. Every site picks up odd, spammy links from scraper sites over time, and Google's systems are built to ignore them.

Google's disavow links help page says to disavow only when you have many spammy or low-quality links pointing to your site, and those links have caused, or are likely to cause, a manual action. That typically means links someone bought or built for you in the past. Google calls disavowing an advanced feature that can harm your search performance if used incorrectly.

If you do need it, the file is plain text: one URL or one domain:example.com line per entry, up to 100,000 lines and 2 MB, encoded in UTF-8 or 7-bit ASCII. Google says it can take a few weeks to take effect, and disavowed links still appear in the Links report. Where you can, ask for the links to be removed at the source first.

How does MrKeyword find backlinks?

MrKeyword shows backlinks it has seen itself, from its own crawler and the MrKeyword web graph, and labels the source of every referring domain. It buys no third-party backlink data and never scrapes Google. Here is what it does with links:

• Backlink checker. For any domain: referring domains, the page-level backlinks MrKeyword's crawler has seen with their anchor text and whether each is followed or nofollow, and domains gained or lost between web graph releases. For a website in your own workspace, the Backlinks view also labels links as followed, nofollow, sponsored or ugc, and counts text, image and empty links.
• Your own sites, from your own connections. For a website in your workspace, MrKeyword adds the linking pages Bing Webmaster Tools reports when Bing is connected, and links you import from your own Search Console or Ahrefs Webmaster Tools exports.
• Backlink Audit. Each referring domain gets a toxicity score built from warning signs listed in plain words, each with its points, so you can see why. You mark each one Keep, Remove or Disavow, and MrKeyword writes a Google-format disavow.txt for the ones you chose. It never submits anything to Google for you.
• Link Building. Prospects from the competitor gap (sites that link to your competitors but not to you) and pages that mention your brand without linking, with a simple outreach tracker. No email is ever sent for you.
• Link Monitor and broken backlink recovery. Paste the pages where you know you have links (directory profiles, guest posts, press) and MrKeyword checks them weekly. Pages of yours that answer an error while other sites still link to them get a suggested 301 target and ready-to-paste redirect rules.

What does MrKeyword not do with backlinks?

MrKeyword does not see every link on the web, does not sell or build links, and does not show Moz, Ahrefs or Semrush metrics. To be specific about the limits:

• Its link index is smaller than the big commercial backlink databases. It covers what MrKeyword's crawler and web graph have seen, plus what your own Bing connection and imports add. The Ahrefs alternative page says plainly when a dedicated link tool is the better choice.
• It does not show Google's own list of your links. Only Search Console does that, and only for sites you verify.
• It does not predict that a link will move your rankings. It shows the link, its source and its date; your Search Console clicks and impressions show what actually changed.
• It does not buy, sell or exchange links, run private blog networks or send outreach email on your behalf.

If you want the full set of free tools in one place, the free SEO tools page lists every one, from the backlink checker to the redirect checker.

Questions and answers