# What Topics Your Competitors Cover That You Don't — Heading Gap Audit Enter your article URL + 2-5 competitor URLs ranking for the same query. The tool extracts every H2 and H3 from each, builds the union of topics, shows what competitors cover that you don't (and vice versa), and scores your topical coverage %. Free alternative to Clearscope and Surfer. Author: J.A. Watte Published: April 28, 2026 Source: https://jwatte.com/blog/blog-tool-heading-gap-audit/ --- Clearscope and Surfer charge $99-$399/month to tell you which subtopics your competitors cover and you don't. The measurement they run is public — extract H2 and H3 headings from the top-ranking pages, cluster by topic similarity, show what's missing. The [Heading Gap Audit](/tools/heading-gap-audit/) runs the same measurement for free. Paste your article URL plus 2-5 competitor URLs. Output: topical coverage %, missing-topic list, unique-to-you list, and an AI outline-fix prompt. ## How matching works H2 and H3 headings from all pages are clustered by token-overlap similarity (Jaccard ≥ 0.5). Each cluster represents one subtopic. For each cluster, the tool checks whether any of your headings match it (Jaccard ≥ 0.45 — slightly lower threshold because cross-competitor matching is stricter than mine-vs-theirs). A topic covered by 3 of 5 competitors but not you is a strong candidate to add. A topic covered by 1 of 5 is niche — may be tangent not worth adding. A topic only you cover is differentiation — but it could also be an unfocused tangent; review before keeping. ## What the output looks like Three sections: 1. **Competitor topic clusters with coverage indicator.** Every subtopic from competitor pages, sorted by competitor-count descending. Green border = you cover it. Red border = you don't. 2. **Unique-to-you topics.** Your H2/H3s that don't match any competitor cluster. Review whether genuine differentiation or just tangent. 3. **AI outline-fix prompt.** Paste into Claude / ChatGPT → get new H2 sections + one-paragraph bodies for the missing topics, grouped into a publishable revision. ## Why H2/H3 and not content depth Headings are a strong proxy for what the page covers without needing to parse full content. Two articles with similar H2 structure usually cover similar topics in the same depth. A paid tool's "content score" is a more sophisticated signal, but the heading-gap signal catches 70-80% of real gaps. For content-depth analysis beyond headings, follow up with [Passage Retrievability](/tools/passage-retrievability/) on each new section as you write it, and [AI Citation Readiness](/tools/ai-citation-readiness/) on the finished article. ## Related reading - [Headings Outline](/tools/headings-outline/) — single-URL H1-H6 outline + errors - [FAQ Harvester](/tools/faq-harvester/) — pulls FAQPage content from top-10 SERP - [Keyword Inspection](/tools/keyword-inspection/) — SERP top-10 analysis ## Fact-check notes and sources - Clearscope methodology (content score): [clearscope.io/about](https://www.clearscope.io/) - Surfer content editor: [surferseo.com](https://surferseo.com/) - Jaccard index: [en.wikipedia.org/wiki/Jaccard_index](https://en.wikipedia.org/wiki/Jaccard_index) --- *The $20 Dollar Agency covers content-gap audits as a recurring client deliverable. The tool is the measurement half; the book is the pricing and packaging half.* --- Canonical HTML: https://jwatte.com/blog/blog-tool-heading-gap-audit/ RSS: https://jwatte.com/feed.xml JSON Feed: https://jwatte.com/feed.json Hero image: https://jwatte.com/images/blog-tool-heading-gap-audit.webp