Domain Authority Checker

Domain Authority (DA) is a proprietary metric created by Moz, calculated from Moz's own massive, continuously-updated link index using a machine learning model trained to predict how well a domain is likely to rank in search results, scored on a 1-100 logarithmic scale. Because it's proprietary and depends entirely on Moz's own crawled data and model, it's only accessible through Moz's paid API or subscription products — there is no free or open way to calculate an equivalent score, which is why this tool is upfront that it doesn't provide one and instead shows every free technical metric it can check.

No — Moz has always been explicit that DA is a third-party metric meant to help SEO practitioners compare relative link strength between sites, not a signal Google itself uses in its ranking algorithm. Google has stated multiple times that it doesn't use DA (or any competing third-party 'authority score' from Ahrefs, SEMrush, or similar tools) directly. It's genuinely useful as a comparative benchmark between similar sites, but it's a proxy metric, not a component of how Google actually ranks pages.

Domain age (from WHOIS) is a loose, imperfect proxy for established trust — older domains have simply had more time to accumulate backlinks, traffic history, and search engine confidence, though age alone guarantees nothing. DNS record count and SSL validity are technical health signals: a domain with a properly configured DNS setup and a valid SSL certificate is easier for search engines to crawl and trust. robots.txt and sitemap.xml presence indicate whether a site is actively managing how search engines discover and crawl its content. None of these directly equal 'authority,' but together they paint a useful technical health picture.

Domain age itself isn't a confirmed direct Google ranking factor (Google has stated it doesn't specifically reward old domains just for being old), but it correlates strongly with things that do matter: more time to accumulate genuine backlinks, more historical content and traffic data for search engines to evaluate, and more opportunity to build topical authority in a subject area. A brand new domain isn't penalized for being new, but it also hasn't had time to build any of those genuinely valuable signals yet — which is the real reason older, established domains tend to perform better on average.

It checks whether the certificate is currently valid and trusted, who issued it (the certificate authority), and how many days remain before it expires. HTTPS (which requires a valid SSL/TLS certificate) has been a confirmed, if lightweight, Google ranking signal since 2014, and beyond the direct SEO impact, an expired or invalid certificate triggers a scary browser warning that drives visitors away immediately — making SSL health a rare metric that matters for SEO, security, and conversion rate all at once.

Those platforms' free tiers typically let you check a limited number of domains per day or month against their own proprietary indexes (Moz's DA/PA, Ahrefs' DR, SEMrush's Authority Score), each requiring you to create a free account and log in. This tool requires no account, no API key, and no rate-limited free tier — it performs real-time technical checks (WHOIS, DNS, SSL, robots.txt, sitemap) directly, which is a different and more limited category of data than a proprietary authority score, but genuinely unlimited and immediate.

Yes, easily — a domain could be five years old with a valid SSL certificate, a clean DNS setup, and a published sitemap, yet have almost no real backlink profile or search visibility, while a newer domain with a genuinely strong content and link-building strategy could be gaining ground faster. Technical health (what this tool checks) is a necessary foundation, but it's not the same thing as the accumulated trust and link equity that Domain Authority and similar proprietary scores actually attempt to measure.

A missing sitemap.xml is a minor, easily fixable gap — sitemaps help search engines discover pages faster but aren't strictly required for indexing, especially on smaller sites with good internal linking. A missing robots.txt is even less concerning by itself (search engines default to crawling everything if no robots.txt exists at all), though it does mean the site owner has no explicit crawl directives in place. Neither missing file is inherently damaging, but both are quick, free wins worth addressing if you're actively working on a site's technical SEO.