Backlinks and SEO: How They Affect Rankings and How to Earn Them

Backlinks — links from other websites to your pages — remain one of the most powerful ranking signals in Google's algorithm. When Google's founders built PageRank in 1998, the core insight was that a link from one page to another is a vote of confidence: pages with more high-quality links pointing to them tend to be more authoritative and more useful than pages with few links.

Over 25 years later, that insight still holds. Google has become far more sophisticated at evaluating link quality, but the fundamental mechanism — links as signals of trust and authority — remains central to how pages rank for competitive queries.

This guide covers how backlinks affect rankings, what makes a link valuable or harmful, and the most effective ways to earn links that compound over time.

How backlinks affect Google rankings

PageRank and authority transfer. Google's core link-based signal is PageRank — an algorithm that assigns a score to every page based on the quantity and quality of links pointing to it. A link from a high-PageRank page transfers more authority than a link from a low-PageRank page. Links from sites that are themselves well-linked are more valuable than links from sites with few backlinks.

The key insight: PageRank flows through links. A link from the New York Times homepage is more valuable than a link from a brand-new blog because the NYT homepage receives links from thousands of authoritative sources, making each link it gives carry significant weight.

Dofollow vs. nofollow. By default, links are followed — PageRank flows through them. When a linking page adds rel="nofollow" to a link, it signals to Google not to pass link equity through it. Common sources of nofollow links: social media platforms, Wikipedia, news site comment sections, press releases, and paid/sponsored links (which should use rel="sponsored" per Google's guidelines).

Nofollow links don't directly pass PageRank, but they can still drive traffic and contribute to brand visibility. A viral link from Reddit with rel="nofollow" may send thousands of visitors to your page and indirectly result in followed editorial links from journalists and bloggers who discover your content.

Domain authority vs. page authority. Link authority operates at two levels: the linking domain and the linking page. A link from a high-authority domain (bbc.co.uk, techcrunch.com) is valuable even if the specific page linking to you is low-traffic. A link from a page that is itself receiving many links (the homepage of a major publication, a heavily-cited resource page) is particularly powerful because it transfers both page-level and domain-level authority.

Anchor text. The clickable text of a link is a relevance signal — it tells Google what the destination page is about. A link with anchor text "canonical URL guide" contributes to the destination page's relevance for queries about canonical URLs. However, an unnatural anchor text profile — where most links to a page use the exact keyword as anchor text — is a spam signal (Penguin algorithm). Natural link profiles have diverse anchor text: brand name, URL, generic ("click here"), partial match keywords, and exact match keywords in small proportions.

What makes a backlink valuable

Not all links are equal. A single link from a highly relevant, authoritative source can be worth more than 100 links from low-quality sites. The key quality signals:

Relevance. A backlink from a page that's topically related to the destination page is more valuable than one from an unrelated site. A link from a marketing blog to your SEO tool carries more weight than a link from a cooking blog to the same page. Topical relevance helps Google understand that the link is editorially meaningful — the linking site's audience would genuinely care about the destination.

Authority of the linking domain. Measured by tools as Domain Authority (Moz), Domain Rating (Ahrefs), Trust Flow (Majestic), or Citation Flow. These are third-party approximations of PageRank, not Google's actual scores — but they correlate well with link value in practice. A link from a site with DR 80+ is worth far more than one from a DR 10 site.

Placement on the page. A link in the main editorial body of an article carries more weight than a link in the footer, sidebar, or navigation. Links that are contextually embedded in relevant content (the linking site is discussing exactly the topic your page covers) signal genuine editorial intent.

The link being followed. Dofollow links pass PageRank; nofollow links don't (though Google says it may use nofollow as a hint). For building ranking authority, you need followed editorial links.

Uniqueness of referring domains. 100 links from 100 different domains is significantly more valuable than 100 links from 1 domain. Referring domain diversity is a stronger signal than raw link count. The first link from any domain carries the most weight; subsequent links from the same domain have diminishing returns.

What makes a backlink harmful

Some links can hurt rankings rather than help them:

Links from link schemes. Buying links, participating in reciprocal link exchanges, or using private blog networks (PBNs) violates Google's guidelines. If detected, these links can trigger a manual penalty (deindexing) or algorithmic suppression (Penguin). The risk isn't worth the temporary gain.

Toxic links. Links from sites with no topical relevance, very low authority, or spam indicators (keyword-stuffed anchor text, low-quality content, irrelevant niche) can be ignored by Google or, if they appear in large volumes, may contribute to a toxic link profile. Most sites don't need to worry about individual toxic links — Google ignores most of them — but a sustained inflow of spammy links at scale warrants using the Disavow Tool.

Exact-match anchor text in bulk. A natural link profile has diverse anchor text. If 80% of links to a page use the exact target keyword as anchor text ("buy running shoes online"), that pattern looks manipulated. Penguin penalises exact-match anchor text over-optimisation.

How many backlinks do you need to rank?

There is no universal number — it depends entirely on the competitive landscape for the specific query. The right approach: analyse the pages currently ranking in positions 1–5 for your target query. Check their referring domain counts and domain authority in Ahrefs, Moz, or a similar tool. To compete, your page needs a comparable (or better) link profile, combined with better content.

For informational queries on new or niche topics, 0–10 high-quality backlinks may be enough to rank. For commercial queries in established markets ("best CRM software", "project management tool"), the top-ranking pages often have hundreds to thousands of referring domains built up over years.

This is why content strategy matters: publishing content that no competitor has (original research, free tools, proprietary data) attracts links naturally. The goal is earning links, not building them mechanically to a number.

The most effective ways to earn backlinks

Original research and data. The most reliably linkable content type. If you publish original statistics — audit results, survey data, proprietary research — journalists, bloggers, and industry writers will link to you as a source. "X% of websites fail this SEO check" is a linkable claim; "here's how to do SEO" is not. DeepSEOAnalysis publishes ongoing site audit data at /research specifically as a linkable asset.

Free tools. Tools attract links from three sources: (a) bloggers who include them in resource roundups ("best free SEO tools"); (b) users who share them on social media; (c) publications that cover them in tool review pieces. Each free tool on this site was built partly as a link magnet — tools accumulate links passively over time in a way that articles don't.

Comprehensive guides. The most-linked articles tend to be comprehensive, definitive guides that other content refers to repeatedly as a source. A 3,000-word guide that covers a topic more thoroughly than any competitor will attract links from shorter articles on the same topic that say "for more detail, see…". This requires genuine depth, not just length.

Link reclamation. Find pages on your site that 404 but still receive external backlinks (from content that linked to an old URL). Redirect those 404 pages to the most relevant live page — you're recovering link equity that's currently being lost. Also monitor for brand mentions without links (set up Google Alerts or use a tool like Mention) and reach out to request the link be added.

Digital PR. Creating genuinely newsworthy content — original studies, controversial takes, timely responses to industry events — and pitching to relevant journalists. Digital PR earns links from high-authority news sites and industry publications. The bar is high: the content needs to be actually interesting to journalists and their readers, not just interesting to your marketing team.

Guest posts. Publishing articles on authoritative sites in your niche, with a natural link back to your site. Quality matters: a guest post on a respected industry publication is worth far more than one on a low-quality "write for us" farm. Google has cracked down on large-scale guest posting for link building, but editorial guest contributions to genuine publications remain an effective and legitimate strategy.

How to audit your backlink profile

Google Search Console → Links report. Shows your top linked pages, top linking sites, and top anchor text. Free, uses Google's own data, and available without a third-party subscription. Limited to the most significant links — doesn't show every backlink.

Ahrefs, Moz, or Majestic. Third-party backlink databases with much more complete link indexes. Ahrefs is generally considered the most comprehensive for backlink data. Use these for competitive analysis (comparing your link profile to top-ranking competitors) and for identifying toxic links or reclamation opportunities.

DeepSEOAnalysis full audit. Checks internal link structure, orphan pages, redirect chain issues, and the technical signals that affect how PageRank flows through your site — alongside all 80+ other SEO checks. Shareable via URL, no signup required.

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Frequently asked questions

Are backlinks still important for SEO in 2026?

Yes — backlinks remain one of Google's strongest ranking signals. Google has consistently confirmed this across multiple statements and algorithm documentation leaks. While the weight of backlinks relative to other signals (content quality, Core Web Vitals, E-E-A-T) has shifted somewhat, for competitive queries, the pages that rank #1 almost always have significantly stronger backlink profiles than pages ranking #10. The difference is that low-quality link building (buying links, PBNs) is now heavily penalised, and the value has shifted heavily toward editorial links from relevant, high-authority sources.

How many backlinks do I need to rank on page one?

There's no universal number. The right comparison is to the pages currently ranking in positions 1–5 for your specific target query — check their referring domain counts using a tool like Ahrefs or Moz. For new topics or long-tail queries, 5–20 referring domains may be enough. For highly competitive commercial queries, the top-ranking pages often have hundreds or thousands of referring domains. Rather than chasing a backlink number, focus on creating content worth linking to — the links follow the content quality.

What is a toxic backlink and should I disavow it?

A toxic backlink comes from a site with spam characteristics: very low authority, no topical relevance, keyword-stuffed content, irrelevant niche (e.g. a Russian gambling site linking to an English-language B2B SaaS). Most toxic links are ignored by Google rather than counting against you. You should consider disavowing only if you see a pattern of many toxic links appearing rapidly — which could indicate a negative SEO attack — or if you've received a manual penalty for unnatural links and are submitting a reconsideration request. Don't disavow every low-quality link you find; over-disavowing can remove links that are actually passing value.

Do nofollow links help SEO?

Not directly — nofollow links don't pass PageRank (the primary backlink ranking signal). But they're not worthless: a nofollow link from a high-traffic page drives real visitors to your site, and those visitors may become customers, share your content, or link to it from their own sites (with followed links). Wikipedia links are nofollow but still drive substantial traffic and establish brand credibility. The indirect effects of nofollow links — traffic, brand awareness, and the followed links they may generate — make earning them worthwhile, even if they don't directly boost rankings.