Keyword research is vital. It’s an essential tactic for developing a powerful content strategy, targeting pay per click advertising campaigns and improving search engine optimization.

For many years Google offered what was undoubtedly the most used free tool for conducting research on popular and not so popular keyword phrases with useful information regarding popularity, competition and suggested variations of phrases.

The tool was actually an AdWords offering that effectively helped people do better AdWords planning, but it certainly worked for all manner of research.

Recently Google decided to more tightly integrate the tool with AdWords and rebranded it as AdWords Planner. In addition to requiring users to log in to an AdWords account to access the tool a great deal of useful research functionality has been stripped away. While I found that it was sufficient for most basic research it no longer serves that need very well.

Below are four free alternatives and four paid alternatives that I suggest business owners and marketers consider adding to their resource and research routines.

Free keyword tools

• Wordtracker -  https://freekeywords.wordtracker.com
• Ubersuggest – http://ubersuggest.org/
• SEO Book – http://tools.seobook.com/keyword-tools/seobook/

My favorite paid options

• MOZ – http://moz.com/tools/keyword-difficulty
• Raven Tools – http://raventools.com/tools/research-central/
• KeywordSpy – http://www.keywordspy.com/
• SEMRush – http://www.semrush.com/