The best alternatives to RankScanner are Ubersuggest, Moz Pro, and Topvisor. If these 3 options don't work for you, we've listed a few more alternatives below.
Ubersuggest is a free SEO tool that specializes in generating new keyword ideas. Originally founded as a tool that scraped Google Suggest terms, Ubersuggest was recently acquired by entrepreneur Neil Patel, who has since expanded the feature set significantly.
A Moz Pro subscription includes: access to site tracking with Campaigns, where you can learn how your site health, link building, and keyword performance impact your SEO success; Research Tools that analyze your competitors efforts, support your keyword research process, and show you new opportunities for link building outreach; and a wealth of resources for learning SEO and inbound marketing.