SEO keyword research tools are essential for marketing teams looking to level up their content. Keyword research software can help identify search opportunities that align with a business’ offerings. That SEO strategy is crucial — nearly one-third of internet users 16 or older discover new brands through search engines. The good news is that many free SEO keyword research tools exist. Teams can build a powerful keyword strategy without spending a dime. In this guide, I’ll share the best free and affordable SEO keyword research tools I’ve tested, explain how to use them step-by-step, and show how HubSpot helps you bring it all together inside one connected platform. Table of Contents TL;DR SEO Keyword Research Tools How I Tested the Best Keyword Research Tools Best Free Keyword Research Tools for 2025 How HubSpot Helps With SEO How to Do Keyword Research with Free Tools Pro Tips for Using Free Tools Effectively Frequently Asked Questions About Keyword Research Tools Turn Keyword Research Into Real Results How I Tested the Best Keyword Research Tools TL;DR: The best keyword tools balance data quality, usability, and workflow integration. If you Google “what is the best free keyword research tool?”, you’ll probably get pages of sponsored posts and affiliate lists that don’t tell you much about how these tools actually perform. So, I decided to test them myself. For consistency across tools, I focused on a single keyword, “AI search.” It’s one I optimize for frequently in blog content tied to my podcast, so it…