What Is a Backlink? How Links Work and What Makes One Valuable

A backlink is a link from another website to yours. If a local newspaper writes about your business and links to your site, you have a backlink from that newspaper. Backlinks matter because they are the one major ranking signal you do not control: anyone can write their own page and claim to be the best, and only other people can point at you. Search engines read that pointing as evidence. A page that many credible sites reference is probably worth reading, and that logic has been at the centre of how search works since Google was founded. One link from a respected site in your field is worth more than hundreds from sites that exist to sell links, and understanding why is the whole of this subject.

This page covers how a link actually works, what makes one valuable, where good ones come from, how to audit your own, and what Google's published policies say about the shortcuts.

The anatomy of a link

Four parts of a link matter, and each one is worth recognising.

• The source page. Which page the link sits on, how credible that site is on the subject, and whether the page itself gets any traffic or attention.
• The destination. Which of your URLs it points at. A link to your homepage helps the site broadly. A link to a specific page helps that page compete.
• The anchor text. The visible words the link is attached to. This tells the engine what the destination is about, which is why "click here" wastes the signal and a natural description of the page uses it.
• The attributes. A link can carry a rel attribute that tells engines how to treat it. The three in Google's documented set are nofollow, sponsored for paid or advertising links, and ugc for user generated content such as comments and forum posts.

On those attributes, Google treats them as hints rather than instructions, and a link marked sponsored or nofollow still carries value as a brand mention and still brings human visitors. Marking paid links correctly is the honest and the safe choice: Google's spam policies require it, and the link keeps doing the jobs it was really bought for.

What decides whether a link is worth anything

The single most useful test is the one at the top of that table combined with the one in the middle: would this link exist if search engines did not? A link that a real editor placed because the page helped their reader is the kind that holds its value, because it is the kind the whole system was designed to count. Our page on how link value is decided goes deeper into the mechanics.

Where good links actually come from

There are a small number of repeatable sources, and all of them are versions of being worth referencing.

• Original data. A survey, an analysis of your own operational numbers, a price index for your sector. Journalists and bloggers need numbers to cite and there are never enough of them.
• A genuinely useful free resource. A calculator, a template, a definitive reference page. People link to things they want to send to a colleague.
• Expert commentary. Being the person quoted when something happens in your industry. This requires being reachable and quick more than it requires a budget.
• Relationships you already have. Suppliers, partners, trade bodies, professional associations, your accountant's client list, the venues you supply. These links are easy, legitimate and almost always unclaimed.
• Local and community involvement. Sponsorships, chambers of commerce, charity partnerships, local press. For a business serving a geography these are among the strongest links available.
• Being the best page on a subject. The slowest and most durable source. Pages that rank get linked to by people writing about the subject, which is a loop that strengthens itself.

Our page on what earns links now works through each of these as a campaign you can actually run.

What Google's spam policies say about shortcuts

Google publishes its spam policies openly, and link schemes are named directly. The documented examples include buying or selling links that pass ranking credit, excessive link exchanges along the lines of "link to me and I will link to you", large scale article marketing with keyword rich anchor text, automated link building programmes, and requiring a link as a condition of a contract or a service.

The important detail is that these policies describe intent. Paying for advertising is normal commercial activity, and Google's requirement is simply that paid links be marked with the sponsored or nofollow attribute so they are not counted as editorial recommendations. Marked correctly, a paid placement is a legitimate advertisement. Unmarked, it is the thing the policy names.

Google's guidance for businesses hiring SEO help is also relevant here: it states that no one can guarantee a number one ranking in Google, and it advises caution with anyone unwilling to explain clearly what they intend to do. A supplier offering a fixed number of links per month for a flat fee is describing a process that produces the links the policies name, because genuinely earned links cannot be committed to by the dozen.

Internal links, outbound links and the other kinds

Three terms get mixed up, and separating them clarifies a lot.

• Backlink or inbound link. Another site links to you. This is what this page is about.
• Internal link. One of your pages links to another of your pages. You control these completely, which makes them the most under used asset in SEO: they distribute credibility around your own site and tell the engine which page owns which subject. Our internal linking guide covers the audit that finds the gaps.
• Outbound link. You link to somebody else. Linking out to sources strengthens a page rather than weakening it, because citing evidence is what a trustworthy document does. Our page on when to link out and how to mark it covers the practice.

There is also the citation, which is a mention of your business name, address and phone number without a link, on directories and listing sites. These matter for local search in their own right, independently of link value, and consistency across them is the thing that counts. Our guide to which citations still matter and how to fix inconsistency covers the audit.

How to check the links you already have

• Google Search Console, Links report. Free, and it shows your top linking sites, your most linked pages and your most common anchor text. Start here, because it is Google's own view.
• Bing Webmaster Tools. A second free perspective, and verifying your site there takes minutes.
• A dedicated backlink tool. Paid tools maintain their own crawls and often show links Search Console does not, along with metrics for comparing sources. Useful for competitor analysis most of all.

When you look, check three things: whether your most important commercial pages have any links at all, whether anchor text looks natural or repetitive, and whether anything is pointing at pages that no longer exist. That last one is quietly common and easy to fix with a redirect, which recovers value you have already earned.

What to do about links you do not want

Google's systems are designed to ignore the great majority of low quality links without any action from you, and for most sites the right response to spam links appearing in a report is to carry on. Google maintains a disavow tool for the specific case of a site that has taken part in link schemes and needs to tell Google which links to discount, and its own documentation describes it as an advanced feature to use when you have a manual action or genuinely expect one. For a normal business site, time spent building one good link beats time spent disavowing fifty bad ones.

a Backlink? How Links Work: the parts people ask about twice

How many backlinks do I need to rank?

There is no threshold, because it depends entirely on what you are competing against. The useful version of the question is comparative: look at the pages ranking for your target query and at the links pointing to those specific pages. That tells you the bar for that query, which is often much lower than the bar for the homepage of a large competitor.

Are nofollow links worthless?

No. Google treats link attributes as hints, and a nofollow or sponsored link still sends real visitors, still puts your name in front of a relevant audience, and still contributes to the overall picture of a brand being discussed. A link from a major publication is worth having whatever attribute it carries.

Should I buy backlinks?

Buying links that pass ranking credit is named directly in Google's spam policies, and the sites that sell them are exactly the sites whose links carry least weight, so it is a poor purchase on both counts. Buying advertising or sponsorship, marked with the sponsored attribute, is normal and legitimate. The difference is disclosure.

How long does a new backlink take to have an effect?

The engine has to crawl the page the link sits on before it counts, which can be days for an active site or longer for a quiet one. The effect then shows as the destination page is re evaluated. Treat links as a quarterly investment rather than a weekly lever.

What is the easiest first backlink for a small business?

The relationships you already have. Suppliers with a partner page, your trade association, the chamber of commerce, any organisation you sponsor, your professional body, and local press for anything genuinely newsworthy. Most small businesses have five or six of these available and unclaimed.

Do links from social media count as backlinks?

Most links posted on social platforms carry the nofollow or ugc attribute, so they are not editorial votes in the ranking sense. They are still valuable, because they put your page in front of the people who write the kind of pages that do link to you. Social is the distribution step that earns the links, rather than the link itself.

This page explains what backlinks are and what makes them valuable. For running an acquisition programme, see the link building guide linked above; for the split between on site and off site work, see our onsite and offsite SEO page.

The reference that is not a link at all

Links are how one website vouches for another. There is now a second form of being referenced, and it leaves no link behind. When somebody asks ChatGPT, Gemini, Perplexity or Google's AI panel which businesses to consider, the answer names two or three, and those names are drawn from pages the system read. Being named in that answer works like a recommendation and produces no referral link in your analytics, so it is invisible unless you go and ask the question yourself. The sources that get used are mostly the same ones that give you good links: the credible, factual pages in your field that actually describe you. Worth seeing which of them the assistants are using. AI Knows Us runs your buyers' questions across the main assistants and shows which sources each answer was built from.