What is a backlink?
By Tom · Last reviewed · 5 minute read
A backlink (also called an inbound link or incoming link) is a link from one website to another. Search engines like Google treat backlinks as votes of confidence, a sign that your content is worth referencing, and they are one of the most important ranking factors in SEO, with quality mattering far more than quantity.
On this page
How backlinks influence search rankings
Understanding the mechanics behind link-based ranking helps you build a stronger SEO strategy.
Links as votes of confidence
When website A links to website B, it is essentially telling search engines: "This content is valuable enough that I want my visitors to see it." Google's original PageRank algorithm was built on this idea: the more quality "votes" (backlinks) a page receives, the more authoritative it appears.
Authority flows through links
Links pass "authority" or "link equity" from one page to another. A link from a highly trusted website (like the BBC or a government site) passes more authority than a link from a brand-new blog. This authority helps the receiving page rank better for relevant searches.
Context and relevance matter
Search engines consider the context around a link. A link to a Cardiff web designer from a Welsh business directory is more valuable than the same link from an unrelated foreign website. The anchor text (the clickable text of the link) also tells search engines what the linked page is about.
Natural link profiles win
Google's algorithms are good at spotting unnatural link patterns. A healthy backlink profile grows gradually over time, includes a mix of dofollow and nofollow links, uses varied anchor text, and comes from diverse but relevant sources. Sudden spikes or patterns that suggest manipulation can trigger penalties.
Quality versus quantity
Not all backlinks are equal. Here is how the common types compare.
Editorial links (highest value)
Links earned naturally when other websites reference your content because it is genuinely useful. These are the gold standard. For example:
- A news site citing your original research
- A blogger recommending your tool or service
- An industry publication quoting your expertise
Guest post links (high value)
Links earned by contributing useful content to other websites. They must be done ethically, with genuine, high-quality content. For example:
- Writing expert articles for industry blogs
- Contributing to relevant online publications
- Sharing expertise on partner websites
Directory links (medium value)
Links from business directories and industry listings. Quality varies a lot, so stick to reputable, relevant directories. For example:
- Yell.com and other trusted UK directories
- Industry-specific directories
- Local business associations
Social profile links (low to medium value)
Links from your social media profiles. They are usually nofollow, but useful for brand visibility and bringing in visitors. For example:
- LinkedIn company page
- Facebook business page
- X (Twitter) profile bio
How to build quality backlinks
Sustainable link building is about earning links through genuine value, not manipulation. These strategies work long-term without risking Google penalties.
Create linkable assets
Develop content that naturally attracts links: original research, thorough guides, useful tools or unique data.
- Run original surveys or research in your industry
- Write thorough guides on the questions your customers ask
- Build free tools or calculators your audience finds useful
- Publish industry statistics or trend reports
Digital PR
Get featured in news outlets, industry publications and blogs by providing expert commentary or newsworthy stories.
- Sign up for journalist request services like ResponseSource
- Build relationships with relevant journalists
- Create newsworthy content or announcements
- Offer expert commentary on industry trends
Guest posting
Contribute useful content to relevant websites in exchange for a link back to your site.
- Target sites genuinely relevant to your industry
- Pitch unique, useful content ideas
- Write high-quality, original articles
- Avoid sites that accept anything for a fee
Local link building
Build links from local organisations, news sites and businesses in your area.
- Join local business associations and chambers of commerce
- Sponsor local events or charities
- Get featured in local news for community involvement
- Partner with complementary local businesses
Broken link building
Find broken links on relevant websites and suggest your content as a replacement.
- Use tools to find broken links on target sites
- Create or identify content that matches the broken link's topic
- Get in touch helpfully, offering your resource as a replacement
- Focus on genuinely useful suggestions
Toxic backlinks and how to handle them
Not all backlinks help your site. These are the warning signs of harmful links.
| Warning sign | What it looks like | Risk |
|---|---|---|
| Links from irrelevant sites | Links from websites completely unrelated to your industry (for example, a gambling site linking to a local bakery) | High |
| Links from link farms or PBNs | Networks of low-quality sites created only to manipulate search rankings | Critical |
| Paid links without disclosure | Links bought without a rel='sponsored' or nofollow attribute, which breaks Google's guidelines | Critical |
| Excessive exact-match anchor text | Most links using your target keywords as anchor text (for example, 'cheap web design Cardiff' again and again) | High |
| Links from foreign-language spam sites | Random links from low-quality sites in languages unrelated to your business | Medium |
| Site-wide footer or sidebar links | Links on every page of a website in the footer or sidebar, often from link exchanges | Medium |
How to disavow toxic backlinks
If you have found harmful backlinks pointing to your site, Google provides a Disavow Tool to tell it to ignore them. Use it carefully: disavowing legitimate links can hurt your rankings.
- Audit your backlinks. Use Google Search Console and tools like Ahrefs or Semrush to find all the links pointing to your site.
- Identify toxic links. Look for the warning signs above. Focus on clearly harmful links, not just low-quality ones.
- Try to remove them first. Contact the site owners and ask for the links to be removed before using the Disavow Tool. Keep a record of your attempts.
- Create a disavow file. List the URLs or domains you want Google to ignore in a text file, following Google's format.
- Submit it through Search Console. Upload your disavow file with Google Search Console's Disavow Links tool.
For the bigger picture, see what SEO is.
Questions people ask
What is a backlink?
A backlink (also called an inbound link or incoming link) is a hyperlink from one website to another. When website A links to website B, website B has received a backlink from website A. Search engines like Google view backlinks as votes of confidence: each quality backlink signals that your content is valuable and trustworthy enough for other websites to reference.
Why do backlinks matter for SEO?
Backlinks are one of Google's most important ranking factors. They act as third-party endorsements of your content. When reputable websites link to yours, it signals to search engines that your content is authoritative and trustworthy. Websites with more high-quality backlinks typically rank higher in search results. However, the quality of links matters far more than the quantity: one link from a respected industry website can be worth more than hundreds of low-quality links.
What makes a good backlink?
A good backlink comes from a relevant, authoritative website in your industry or niche. Key factors include the linking site's authority and trustworthiness, relevance to your topic or industry, the link being placed within the main content (not footers or sidebars), natural anchor text, and the linking page itself having quality backlinks. Links from government sites, universities, major news sites and respected industry publications are particularly valuable.
What is the difference between dofollow and nofollow links?
Dofollow links pass SEO value (often called 'link juice') from the linking site to your site, helping improve your search rankings. Nofollow links include a rel='nofollow' attribute that tells search engines not to pass ranking value. While nofollow links do not directly boost rankings, they can still drive referral traffic and brand awareness. Google has also introduced rel='sponsored' for paid links and rel='ugc' for user-generated content like comments.
How can I get backlinks to my website?
Ethical link building strategies include creating valuable content that others naturally want to reference, guest posting on relevant industry websites, building relationships with journalists and bloggers for digital PR, getting listed in reputable business directories, creating shareable resources like tools or original research, engaging with your local business community, and asking satisfied customers or partners for links. Never buy links or take part in link schemes, as these break Google's guidelines.
How many backlinks do I need to rank well?
There is no magic number. It depends entirely on your competition and industry. A local plumber in a small town might rank well with a handful of quality local links, while a national online shop might need thousands. Focus on quality over quantity, and look at your top-ranking competitors to understand the backlink landscape in your market. Consistent, gradual link building over time is more effective and safer than trying to get lots of links quickly.
Can backlinks hurt my website?
Yes, toxic or spammy backlinks can harm your rankings. Google's algorithms can penalise sites with unnatural link profiles, including paid links, links from link farms or private blog networks (PBNs), excessive exact-match anchor text, and links from irrelevant or low-quality sites. If you have been hit by a penalty or notice suspicious links pointing to your site, you can use Google's Disavow Tool to tell Google to ignore those links.
How can I check my backlinks?
You can check your backlinks with Google Search Console (free, and shows a sample of the links Google has found) or with paid tools such as Ahrefs, Moz, Semrush or Majestic. These show which sites link to you, the anchor text used, whether links are dofollow or nofollow, and help identify potentially harmful links. Regular backlink audits help you understand your link profile and spot issues early.