Domain Authority (DA)
Definition: Domain Authority is a third-party score from Moz, on a 1 to 100 scale, that predicts how likely a domain is to rank based mainly on its link profile; Google does not use it, and other tools publish similar scores.
Also called: DA, Domain Rating (DR), Authority Score, website authority
Updated
Third-party scores, not Google scores
Domain Authority is Moz’s metric. Ahrefs publishes Domain Rating (DR), Semrush publishes Authority Score, and several smaller tools have their own versions. Each is calculated by its vendor from its own link index with its own formula. None of them comes from Google, and Google does not use them in ranking.
They became the default shorthand after Google stopped publishing a public PageRank score, because people still wanted a quick way to size up a site’s link profile. As shorthand they are useful. As a target they are misleading.
How to use them sensibly
- Compare within one tool. A DA of 40 and a DR of 40 are not the same thing.
- Compare sites in the same niche. A score means more relative to direct competitors than in the abstract.
- Expect the scale to get harder. The scores are logarithmic or close to it, so moving from 20 to 30 is far easier than from 70 to 80.
- Read changes with caution. A score can drop because the vendor recalibrated its index, not because anything happened to your site.
Open PageRank, a free score computed from the open Common Crawl link graph, is sometimes used as a vendor-independent comparison point; the domain authority checker uses a commercial link index.
Mistakes these scores encourage
- Buying links “from DA 50+ sites”, which puts the metric ahead of relevance and risks breaking Google’s link spam policy.
- Choosing outreach targets by score alone, ignoring whether anyone reads the site.
- Reporting the score as the main SEO KPI, instead of rankings, traffic or leads.
Our view: treat authority scores as a thermometer, not a thermostat. The domain authority checker gives a score with context, and the backlink analysis guide explains what sits behind the number.