Screaming Frog SEO Spider - The Screaming Frog SEO Spider is a small desktop program (PC or Mac) which crawls websites’ links...
KeywordTool.io - KeywordTool.io is the best FREE alternative to Google Keyword Planner and Ubersuggest. It uses Google's autocomplete feature to get over 750+ long-tail keywords for any given query.
SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.
Google Trends - Explore Google trending search topics with Google Trends.
Pulno - SEO Audit and Website Analysis. Pull up your SEO.
Keywords Everywhere - Free browser add-on for keyword volume, CPC & competition