As an Open Source Intelligence (OSINT) trainer for Social-Engineer, LLC and a speaker on the topic, one of the most frequent questions I get is, “What is your favorite OSINT tool?” There are hundreds, if not thousands, of OSINT tools available to a researcher, so picking one tool to recommend when asked this tends to be difficult. I like to approach this question with my own question, “What are you looking for when researching?” I think that is an important question a researcher must answer before they start an investigation. There is no one tool to rule them all, no matter what anyone tells you. Every investigation is different. Your approach should keep that in mind from the very beginning.
Michael Bazzell makes a great point that OSINT is more of a mindset or philosophy and relying on any single tool, such as his own personalized search tools on his website that he eventually had to remove, could disappear at any time and leave you hamstrung if you don’t diversify and continually educate.