There are plenty of SEO tools out there. You can find both free and premium tools. They offer similar services, yet using different tools may give you different results, too. That’s because they often have different algorithms. Using more programs isn’t always the best idea.
Google, for example, offers a free service called Google Search Console, which provides access to a bunch of different tools. At the end of the day, it depends on what you use for your website. For example, if you run a WordPress website, the Yoast SEO plugin is also free and quite simple to implement.