Surfer

Surfer turns SEO writing into something closer to a game. You enter a keyword, and the Content Editor shows a score that climbs as you cover the terms, headings and topics that top-ranking pages tend to include.

We like it because it takes the guesswork out of briefing writers. Instead of a vague instruction to make it SEO-friendly, you can hand someone a target score and a list of terms. It also plugs into Google Docs and WordPress, so writers do not have to change where they work.

At $99 a month it is not cheap, and chasing a perfect score can lead to stiff, keyword-stuffed writing. Used with a bit of judgment, though, it is a reliable guide for teams that publish regularly.