Moz offers a free version of its link analysis tool, which allows you to check your website's backlink profile, track link metrics, and find potential link opportunities. The free version limits the number of link queries you can perform each month.
Ahrefs also offers a free version of its backlink checker tool, which provides information on the top 100 backlinks to any website or URL you enter. This can help you identify potential link opportunities and track your backlink profile.
This tool helps you find email addresses for potential link prospects. It provides a domain search feature that allows you to find email addresses associated with a particular website or domain.
Receive and respond to requests for sources and quotes for journalists. It can also be used as a link-building tool, as you can respond to reporter requests and potentially earn a backlink to your website if your response is selected and included in the article.
Manage projects and leads from your Gmail account. Streak is a free email tracking tool that can be used for link-building outreach.