Off-Page
Backlink
Also known as: inbound link, external link
A backlink is a hyperlink from one website to another. Google originally built PageRank around them (one site linking to another as a vote of confidence) and they remain a primary ranking signal in 2026 — but with materially different weighting than in 2010. Quality, contextual relevance, and editorial nature matter far more than raw quantity. A single tier-1 editorial backlink can outweigh thousands of low-quality ones.
What makes a backlink valuable
| Factor | Why it matters |
|---|---|
| Source domain authority | Higher = more equity passed |
| Topical relevance | A SaaS-relevant link from a SaaS blog beats a generic link from a high-DA general site |
| Editorial nature | Earned (genuine recommendation) vs paid/exchanged |
| Link placement | In-content paragraph vs sidebar/footer vs comment section |
| Anchor text | Descriptive keyword > branded > generic (“click here”) |
| Linking page’s own backlinks | A link from a heavily-linked page is worth more |
| Follow vs nofollow | Follow passes equity directly; nofollow + sponsored + ugc pass less but still useful |
| Surrounding content quality | Link from a thin spammy page is devalued |
Types Google distinguishes
- Follow (default) — passes link equity
- rel=“nofollow” — hint Google may or may not follow (since 2019)
- rel=“sponsored” — paid links (advertising, affiliate)
- rel=“ugc” — user-generated content links (comments, forums)
Common backlink-acquisition methods
- Digital PR — original research, expert quotes, journalist relationships
- HARO / Connectively / Featured — quote-sourcing services that journalists use
- Resource page outreach — getting added to industry “best of” lists
- Broken link building — find broken links on relevant sites, suggest your page as a replacement
- Guest posting — contributed articles in industry publications (used with discretion in 2026)
- Earned mentions — original research and shareable content that naturally accumulate links
What to avoid in 2026
- Link farms / PBNs — Google detects and penalizes networks of low-value sites linking to each other
- Bulk paid links without proper rel attributes — Penguin and subsequent updates penalize aggressively
- Comment / forum spam
- Exact-match anchor abuse — looks unnatural and triggers Penguin signals
- Footer / sidebar reciprocal exchanges at scale
Measurement
- Ahrefs Domain Rating (DR), Moz Domain Authority (DA), SEMrush Authority Score
- Backlink growth rate per quarter vs competitors
- Referring domain diversity (number of unique linking domains)
- Anchor text distribution (should be diversified, not concentrated)
Related terms
Apply in practice
- Resocial service →
/services/seo/link-building/ - Read on the blog →
/blog/in-house-seo-team-vs-agency/