URL Rating (UR) shows the strength of a page's link profile on a 100-point scale. The bigger the number, the stronger a page's link profile is.
UR is a page-level metric, whereas DR is a domain-level metric. So if you put a website into Ahrefs’ Site Explorer and check its UR, the number you get will be for the homepage alone.
The scale is logarithmic, which means that it’s a lot easier for a page to go from UR 20 to UR 30 than it is to go from UR 70 to UR 80.
Both internal and external links are taken into account.
Our algorithms spot and cut off "linking loops" — the exchanging of rating scores again and again in a loop between two websites.
Q1: "Is UR similar to Google's PageRank?"
We use the same basic PageRank principles to calculate URL Rating (UR).
We count links between pages;
We respect the “nofollow” attribute;
We have a “damping factor”;
We crawl the web far and wide (which is a critical component when calculating an accurate link‐based metric)
With that said, UR is not a direct replacement for PageRank. Google’s PageRank formula has evolved a lot since its inception, while the formula for Ahrefs’ UR remains more simplistic.
Q2: “Why should I use UR, then?"
Nobody knows exactly how PageRank is calculated except Google themselves. But: high UR pages tend to rank higher in organic search results.
Since the formula for UR is based off basic PageRank principles, it correlates well with Google rankings and is a near-perfect way to gauge a page's link profile strength.