While these free tools don’t give you a ton of features to effectively analyze competition, they are FREE and they can definitely help you discover unique and long tail keywords that may be very profitable and you can then take and plug into your paid keyword research tools.
Google Keyword Planner is basically the staple of all SEOs. Google is the big daddy of search, therefore they pretty much have the most accurate data. All you’ll need is a FREE AdWords account, which requires a Gmail account. You can get some information about the keywords you are searching for such as PPC competitiveness and search volume, which can be very helpful. And you may also discover some longer tail keywords that get lower volumes of search, which is often the low hanging fruit that is easy to rank for.
Keyword Tool is a FREE alternative to the Google Keyword Planner and has a much simpler interface. And in addition to getting info on Google, you can actually get keyword ideas across multiple search engines, including YouTube and the App Store. I’m confident this tool will help you uncover some keyword gems that you can further expand upon in more advanced keyword research tools.
Übersuggest is another Google Keyword Planner alternative that is unique because it gives you all sorts of results based on a single keyword phrase. It basically adds related keywords to the beginning and end of your target keyword and can help you think of several different ideas and directions to expand on your keyword list, especially if you’re stuck and can’t seem to think of very many variations.