UberSuggest.org is a free online keyword suggestion tool that allows users to generate keyword ideas by entering a term into the site's query box, choosing a language and a source, and sorting through the given results for desired keywords. KeywordTool.io is a free search engine optimization utility that uses Google Autocomplete to generate a list of long tail keywords. This tool works by prepending and appending a user's specified search term with letters and numbers.
Keyword Tool describes itself as a free online keyword research instrument. The website offers a paid version of the program as well, but the free version of Keyword Tool is capable of generating lists of over 700 keywords in 83 languages including English, German and Spanish. Uber Suggest is a similar keyword generation tool capable of generating lists of thousands of keywords. To use this tool, users select a language and enter a term on the website, which then returns a list of appended words. Users can then select desired suggestions individually or en masse. Uber Suggest is able to generate suggestions from a number of sources including regular web search engines and search verticals such as shopping, news or video. Tools.SEOBook.com offers another good keyword generation tool that creates large lists of permutations of entered terms.