Google Keyword Planner is the best starting point for most businesses because it's free and sources data directly from Google's ad platform. You get actual search volume ranges, seasonal trends, and cost-per-click estimates without spending a dollar. The interface is clunky and the volume ranges are broad unless you run active campaigns, but the data accuracy beats any third-party estimate. For local Canadian businesses, it shows geo-specific volumes for cities like Ottawa, Toronto, or Vancouver, which matters when your service area is regional. Ahrefs is the best paid tool for serious SEO work. At roughly $130 USD monthly for the Lite plan, you get accurate keyword difficulty scores, parent topic identification, SERP feature tracking, and a massive index of keywords most competitors miss. Their clickstream data makes volume estimates more reliable than tools that extrapolate from limited sources. The Content Gap feature alone justifies the cost when you need to find what competitors rank for that you don't. Semrush runs a close second at similar pricing, with stronger position tracking and site audit features bundled in. If you need an all-in-one platform rather than just keyword research, Semrush wins. Moz is cheaper but the keyword index is noticeably smaller, especially for Canadian longtail terms. At Ottawa SEO, we use Google Keyword Planner for initial client discovery and volume validation, then Ahrefs for competitive research and content planning across our portfolio. Free tools like Ubersuggest or AnswerThePublic work for blog ideas but lack the depth for strategic decisions. The worst approach is paying for multiple overlapping tools. Pick one paid platform, learn it thoroughly, and supplement with Keyword Planner's free data. For most small businesses, Keyword Planner plus manual SERP analysis covers 80% of needs without monthly fees.