The Keyword Gap Checker compares your site with a competitor's and lists the topics they cover that you do not cover anywhere. It reads a sample of pages from each site's sitemap, then returns up to 12 topic gaps with a short note on why each matters, the two-word phrases they use often that you do not, and the topics only you cover.
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A keyword gap is a topic a competitor writes about that your site does not. The headline gives the number of gaps found, and the table lists each topic with a one-sentence note on why it matters to you.
Two lists follow the table: two-word phrases the competitor uses at least 3 times that do not appear in your sample, and topics only your site covers.
The tool reads each homepage plus up to 12 pages listed in the site's sitemap.xml. The result describes that sample, so a topic marked as a gap may still exist on a page that was not read.
If a site has no sitemap.xml, or only a sitemap index, the tool can read little more than the homepage. The page counts in the stats show how many pages each sitemap lists.
Not every gap is worth filling. Some topics suit only the competitor's audience.
It does not show search volume, rankings, backlinks or traffic. For a side-by-side of titles, schema and page counts, use the SEO Competitor Analysis.
Related tool: Ready to write a page for a gap? Build an outline with the Content Brief Generator.
Peak Answer runs checks like these every week, then writes the content and gets the placements.