Surfer

Surfer is a content optimization tool. You enter a target keyword and it studies the pages that rank for it, then gives you a content editor with a score, suggested terms, headings and a rough length range based on those pages.

Writers use it while drafting or updating an article, watching the score rise as they cover the topic more fully. It also has AI writing features that draft articles from a brief, a WordPress plugin and a Chrome extension that brings the editor into Google Docs.

The score measures similarity to what already ranks. A high score does not make a page useful or accurate, so treat the term list as a coverage check and keep editing for the reader.