There are a number of free SEO tools out there. From content optimization, backlink analysis, keyword research, on-page SEO, off-page SEO and more.
Below are a few free tools that stand out:
https://seotoolshq.com provides one of the best how to overviews. There’s a choice of 16 different SEO tools on their front page.
https://keywordtool.io/ Free version of Keyword Tool generates up to 750+ long-tail keyword suggestions for every search term
https://keywordseverywhere.com/ The Keywords Everywhere extension is your free keyword tool. It can be easily installed on either Chrome or Firefox. The best part is that we show you useful google keyword search volume, cost per click and competition data of keywords on multiple websites.
https://analytics.google.com/analytics With a tracking code, one can track choices and all kinds of visitor activity on your site.
https://www.similarweb.com See all your competitors traffic, check your market share for effectiveness.