Hey there! Tawny from Moz's Help Team here. I think I can help explain why you're not seeing all the same links you might see with other tools. It has to do with our Mozscape Index, which powers Open Site Explorer.
Open Site Explorer and the Link Analysis page of campaigns are both tied to our Mozscape index, which tends to update roughly once a month.
Just a few points on how we compile our index:
- We grab the most recent index.
- We take the top 10 billion URLs with the highest MozRank (with a fixed limit on some of the larger domains).
- We start crawling from the top down until we've crawled ~130 billion URLs
The idea here is that we're focusing on the highest-quality links we can find, coming from the most prominent pages of authoritative sites. So, while you may not see every link for a site within our index, we're aiming to report the most valuable ones available!
Most new sites and links will be indexed by our spiders and available in Mozscape and Open Site Explorer within 60 days, but some take even longer for many reasons - including the crawl-ability of sites, the number of inbound links to them, and the depth of pages in subdirectories. This biases our tool slightly in favor of newer links; Open Site Explorer only caches older links for about 180 days, so unless the tools re-crawl and index those links, they may fall out of our index after a while.
You can see our most recently updated schedule here as well as some more technical metrics on our Mozscape API Updates page. You can also see when the last and next updates happened on the Open Site Explorer (OSE) homepage at any time.
Since Moz focuses on quality of links over quantity, we are always focused on the most relevant links to display to our users. It's possible that Moz's index will leave out some of the lower-quality (non-link juice providing) links out of our index because of this. So, that might explain why you may see some discrepancies with what other tools may be showing.
I know this is a ton of information, so if you have any questions or if I didn't make anything clear enough, please don't hesitate to ask! Just shoot us a note over at help@moz.com and we'll do our best to help you out.