There are only a few really reliable SEO backlink checkers these days. Over the years, there have been many that have come and gone. But, these have survived and proven themselves to be the best of the best.
When it comes to backlink checking, I think it is worth having all 3 of these in order to get a balanced picture of your link profile. Ultimately, Google Webmaster Tools should be your ultimate guide as to how many total links you have. You can use that number as a benchmark to determine how close these service are for a link profile – if you are looking at your own site (You can find out this number by logging into your WMT account and going to “Traffic>Links To Your Site”.) .
But, if you are just focusing on other sites, this is the best of the best, in order. And, again, I would use all 3 of these:
Ahrefs: This is a latecomer to the SEO industry. And, it is phenomenal. I feel like they have the widest array of information on links. It’s easy to find breakouts by i.p. and TLD. I also love the graphical rendering of the indexing of links over time. Plus, the bulk link checker is the best of the 3. I give this one 2 enthusiastic thumbs up.
Majestic SEO: This is a close #2. Typically, I think their bulk link locating capabilities are on par with Ahrefs. But, the layout just isn’t quite as informative as Ahrefs. Majestic is still a powerful tool that is worth having in your arsenal.
SEOMOZ: While SEOMOZ is still a very helpful tool for SEO, I have not found it’s backlink capabilities to be on par with the others above. I think you will find – in your own research that Moz will routinely find fewer links than Ahrefs or Majestic. But, I think it’s still a great tool to have in your arsenal. I always run a check on Moz backlinks. But, I also use it for so many more things – from keyword rank tracking to on-page optimization guidance. It’s a fantastic tool. And, it still makes sense to be an active member of the Moz community.