SpyFu

SpyFu is built around one question: what is the other site doing. It keeps more than a decade of history on which keywords a domain ranked for, which ads it ran and what it paid, which is the part the general SEO suites treat as a side feature. For research on a competitor rather than maintenance on your own site, it is the cheaper specialist.

Basic is $39 a month for 10,000-row results and exports, one tracked site, API access and one user. Pro is $59 for the first month and $119 after, with unlimited results and exports and ten tracked projects, so read that first-month price as an introduction rather than a rate. Annual billing is stated as three months free, a 25 percent saving, which is where the page's own headline figure of $29 a month comes from.

Anybody researching what a competitor is doing rather than maintaining their own site, which is a narrower job than the big suites are built for and much cheaper here. If you need site audits and backlink monitoring, this is the wrong tool.