Backlink audit (SEO audits)
A backlink audit within the context of a full SEO audit evaluates the quality, risk, and strategic opportunity in a site's external link profile. The audit outcome determines whether the link portfolio is an asset, a neutral factor, or a risk — and what specific actions should be taken to improve it.
Learning objectives
After completing this module, you will be able to:
- Evaluate backlink quality, risk, and opportunities within an SEO audit context.
- Identify valuable links, lost links, weak anchors, and spam patterns.
- Decide when action is needed and when continued monitoring is sufficient.
Referring domains vs backlinks
The distinction is critical. A backlink is a single link. A referring domain is a unique website that links to you. One referring domain may link to you from 500 different pages — but it still counts as one referring domain.
Always evaluate the backlink profile at the referring domain level first, then drill into specific pages for high-value sources or risky patterns.
Link authority and relevance
Authority (domain rating, domain authority) and relevance are both required for a link to have real value.
Authority without relevance: A high-DR link from an unrelated site (e.g., a finance site linking to a pet grooming business) passes some authority but limited topical relevance.
Relevance without authority: A niche blog with DR 20 that is deeply embedded in your industry and trusted by your target audience passes topical relevance and real user traffic signal.
Both: An industry publication with high authority and topical relevance is the most valuable link type.
Evaluate each referring domain on both dimensions.
Anchor text distribution
Review the anchor text used by external referring domains pointing to each key target page:
- Branded anchors should form the largest proportion.
- Exact-match keyword anchors from external sources at high concentrations are a risk.
- Generic anchors (click here, source, read more) are natural and common in editorial content.
For any page with a high proportion of exact-match keyword anchors from unrelated domains, document and monitor carefully.
Lost links
Export "lost links" from Ahrefs or Semrush. These are domains that previously linked to your site but the link is no longer active. Review:
- Why the link was lost (page deleted, content changed, domain expired?).
- Whether the linking page still exists (it may have moved the link or updated content).
- Whether the linked page on your site still exists at the same URL.
High-value lost links from relevant, authoritative sources are reclamation priorities:
- Contact the publisher to request restoration.
- If your linked page was deleted or moved, implement a redirect first.
Broken backlinks
A broken backlink points to a URL on your site that returns 404. This represents lost link equity. Fix by:
- Identify 404 URLs with inbound backlinks (Ahrefs: Best by Links → filter by 404).
- Redirect the 404 URL to the most relevant existing page.
- Equity will flow to the redirect destination.
Risk classification and disavow considerations
Classify each suspicious referring domain pattern:
| Risk category | Characteristics | Action |
|---|---|---|
| Safe | Relevant, editorial, real content | No action |
| Low-quality but benign | No editorial value but not manipulative | Monitor |
| Manipulative pattern | Link farm, PBN, or clear paid-link pattern | Consider for disavow with documentation |
| Spam | Completely irrelevant, automated content | Consider for disavow |
Disavow is a last resort. Do not disavow aggressively. The bar for disavowing is: documented evidence that the links are manipulative and are causing or contributing to a manual action or algorithmic suppression.
Checklist
- High-value referring domains are identified and categorized.
- Lost links are reviewed and high-value ones queued for reclamation.
- Broken linked pages (404) are identified and redirected.
- Anchor text risk is checked per target page.
- Disavow file is used only with documented justification.
Measurement
| Metric | What it tracks |
|---|---|
| High-quality referring domain count | Profile strength |
| Lost link reclamation wins | Recovery of lost equity |
| Broken backlink recovery | Technical fix impact |
| Anchor text diversity by target page | Over-optimization risk monitoring |
| Risk-tier referring domain distribution | Profile health over time |
Common mistakes
Disavowing links too aggressively. Building a long disavow file from an automated tool's "spam score" can remove real links that have value. Manual review is required.
Evaluating links only by domain authority metrics. A DR 30 industry-specific publication is often a better link than a DR 75 content farm.
Not fixing broken linked URLs. A 404 on a URL with 20 referring domains is a fixable equity loss. Prioritize redirects for pages with significant inbound link volume.
Ignoring relevance as a quality signal. An irrelevant link from a high-authority domain has limited topical relevance value. Topical match between the linking page and the linked page matters.
Focusing only on quantity. 1,000 referring domains from article directories is often worth less than 100 referring domains from genuinely relevant, editorial publishers.