In the world of SEO, a link pointing to your site from another site is called a backlink. Google reads them as votes of confidence. The more you receive from relevant sources, the more authority your site gains. And the higher it climbs in the search results.
Why backlinks are the fuel of your SEO
PageRank, Google's founding algorithm, rests on a simple idea: a page receiving many links from other recognised pages is probably trustworthy. That logic is still at the heart of how Google works. Research from Ahrefs on SEO ranking factors confirms that the number and quality of inbound links remain among the factors most correlated with good positions in the search results. And analysis from Semrush on backlinks shows that pages ranking first receive on average 3.8 times more backlinks than those in second place. Without inbound links, even excellent content struggles to climb.
What makes a backlink valuable
Not all links are equal. A link from an authoritative site in your sector is worth infinitely more than a dozen links from generic directories. The key indicators to watch are Domain Rating on Ahrefs and Authority Score on Semrush. A link from a site with a Domain Rating of 70 in your sector is a major SEO asset. A link from a site with no traffic and no history brings you almost nothing.
Basic rule: 1 quality link from a recognised site in your sector is worth more than 50 links from sites with no authority. Quality always beats quantity when it comes to backlinks.
5 methods for earning links without an advertising budget
- Guest articles: offer useful content to a blog or publication in your sector in exchange for a link to your site
- Client testimonials: write a sincere review for a supplier or partner; they will often include a link back to you
- Unlinked mentions: find the sites citing you without a link, and ask them to add one
- Reference content: create guides or resources other sites will naturally want to cite
- Quality directories: list yourself in the recognised registers of your sector, never low-grade generic directories
The unlinked mentions method is often the quickest to put into practice. To find the sites mentioning you without a link, use Google Alerts with your company name and your domain. On each alert, check whether the mention comes with a link. If not, a simple, courteous email is often enough to secure the missing link. Moz on link building strategies also recommends broken link building: identifying broken links on sites in your sector, then offering your content as a replacement.
The mistakes that can get you penalised
Buying links in bulk, joining link exchange networks or using automated content farms are practices Google penalises. A manual penalty can make your site disappear from the results for months. Since the Penguin update was folded into the main algorithm, these practices are detected continuously.
Free tool: if you think you have toxic links pointing at your site, log in to Google Search Console, Links section, and look at the domains citing you. To disavow dubious links, Google provides the Disavow tool directly in Search Console.
Analysing and monitoring your existing backlinks
To see every inbound link to your site and its quality, start with Google Search Console (free): it lists the domains linking to your site, with the number of pages involved. For a more advanced analysis with authority metrics, Ahrefs Site Explorer gives you a complete profile of your backlinks with their quality, the anchors used and how they move over time. Majestic SEO is a recognised alternative with its own Trust Flow and Citation Flow indicators, useful for cross-checking data and validating the quality of your sources.
Where to start today
Open Google Search Console and go to the Links section. Note the current number of referring domains. Then search for your company name on Google. Identify 3 sites mentioning you without linking to you. Write a short, factual email to each. That first piece of work takes under an hour.
Link building amplifies the SEO work you already have in place. If you have not yet structured your internal linking, start there before going after external links. Read our guide to internal linking to make sure every page on your site receives the right authority before concentrating your effort on inbound links.