Glossary
Authority Score
A third-party metric (popularised by Semrush) that estimates a domain's overall strength and trustworthiness on a 0–100 scale, based on backlinks, traffic, and spam signals.
Authority Score is a compound metric that tries to summarise how strong and trustworthy a website is in a single 0–100 number. Semrush's version blends link data (the quantity and quality of referring domains), organic search traffic, and signals that flag spammy or unnatural link patterns. Similar third-party scores include Moz's Domain Authority and Ahrefs' Domain Rating, though each vendor calculates its own way, so numbers don't match across tools. It's important to remember these scores are estimates made by SEO companies, not official ratings from Google. They're useful for comparing sites, vetting link prospects, and tracking your progress over time, but chasing the number itself is a mistake. A high Authority Score generally reflects a site that has earned many quality links and real traffic — the underlying work is what matters. Use it as one input among several when deciding which sites are worth a backlink, and watch your own trend rather than obsessing over a single snapshot.