Domain Authority and Page Authority are metrics created by Moz to estimate ranking strength. DA scores your entire domain on a 0–100 scale, while PA scores individual pages the same way. Both use machine learning models trained on link data—number of linking domains, spam score, anchor text diversity, and the authority of sites linking to you. A DA of 30–40 is typical for most small businesses; 50–60 is solid for established regional players; 70+ is reserved for major brands and publishers. PA scores fluctuate more because they reflect page-level links, so your homepage often has the highest PA on your site. Neither metric comes from Google. They're third-party approximations, useful for comparative analysis but not direct ranking signals. When we evaluate link prospects at Ottawa SEO, we check DA to filter out spammy sites (anything under 20 is usually thin) and to gauge whether a backlink will move the needle. A link from a DA 65 news site carries more weight than one from a DA 18 directory, all else equal. The scores are logarithmic, so jumping from 20 to 30 is easier than 60 to 70. Improving DA requires consistent link acquisition from diverse, relevant domains over months or years. You can't game it with a few high-DA links; breadth and trust matter as much as raw authority. PA responds faster because you can target link equity to specific pages, but it still lags real ranking changes by weeks. Use DA and PA as rough filters and benchmarks—compare your metrics to competitors, vet outreach targets, and track long-term trends. Don't obsess over small fluctuations or treat them as gospel. Moz updates its index periodically, so scores shift even if your link profile hasn't changed. Focus on earning links that drive referral traffic and relevance; authority scores will follow naturally. We track DA quarterly for clients but prioritize actual keyword rankings and organic traffic, which reflect Google's real algorithm.