Having a list of the websites that link to your competitors is one of the first steps to developing an link building campaign that can improve your search engine rankings.

But how can you easily check link popularity of your competition?  Here are a few free link popularity tools that can help.

MarketLeap - this free link popularity tool is an online service.   By typing in your own domain name, and the domains of up to three competitors (optional), it helps you find out who is linking to your site, but also to give a useful benchmarking report to quickly show where you stand in comparison other major online players.

CheckYourLinkPopularity.com - this free link popularity tool is downloadable software. This allows you to check your own domain plus virtually an unlimited number of your competitors (you can import a list of the other sites you want to check easily into this program). The on-screen report you'll get looks like this:

Check free link popularity tool: CheckYourLinkPopularity.com

Also, you'll be able to save your last link popularity check, and you can export the reports to a text (.txt) file for reporting and monitoriing purposes.

Outside of these free tools, another resource is Arelis which is more full-featured software program to help managing your links, link exchanges and link popularity.