Link gap
Link gap means the sites that link to competing pages but not to you. For a small site, this is the shortest qualified list of link prospects. You can find them fast and pitch with context.
By Théophile Louvart, founder of Porteur · Updated 13 September 2026 · Markdown
What link gap means for a small site
You are not trying to win the web. You are trying to win the few sites that already link to pages like yours. Those domains have proven they will link to this topic. That is why the list is small and qualified.
Example: three guides rank for "API rate limits". Two have links from apiblog.example and devnotes.example. Your /guides/api-rate-limits has none. The gap is those two domains and the exact pages they used as sources.
How to find the link gap
Pick the pages to compare
Choose one target page of yours, like /guides/getting-started, and a few rival pages that rank for the same query.
Subtract your set from theirs
Find domains and URLs that link to at least one rival page but not to yours. Keep it at the page level first. Then repeat at the domain level for your whole site.
Score and sort
Score each prospect by topical fit, anchor relevance and the authority you observe in that index. Sort by fit first, then by observed authority.
How to read the numbers
- Referring domains to rivals but not to you: the size of your opportunity list.
- Linking page type: resource page, roundup, forum thread, changelog, documentation. Page type tells you the pitch and link format to expect.
- Anchor and surrounding text: shows the angle that earned the link. Match that angle in your pitch or content.
- Target depth: links to the rival home page, /pricing or a deep guide. If most links are deep, fix your equivalent deep page.
A healthy gap list is specific. It names apiblog.example/post-123 with anchor "API rate limit examples" rather than a vague domain note.
What to do with a link gap list
Tighten your target page
Check on-page basics: title near 60 characters, clear h1, descriptive meta, fast LCP under 2.5 seconds, internal links from relevant pages. Make it the best answer.
Map pitch to page type
For a resource page, offer your guide and why it helps their readers. For a roundup, suggest inclusion and provide a one line summary. For a documentation page, offer a clearer example or correction.
Close content gaps that block links
If rivals earn links for a comparison or a checklist you do not have, ship your /guides/api-rate-limit-checklist or /compare/tool-a-vs-tool-b page first.
Send small, specific pitches
Write to the editor of that one page. Reference the exact sentence that links to a rival. Offer your page as a better or complementary source. Keep it short and specific.
Pick up easy wins
Find broken links among the gap set. If a linking URL 404s or points to a dead resource, offer your equivalent. Fix your own broken backlinks as well.
A fixed case looks like this: your /guides/getting-started gains links from a tools roundup, a university resource page and a dev forum thread soon after targeted outreach.
Traps to avoid
- Comparing home pages only when the query is page level. Always compare like with like.
- Chasing every domain. Start with high fit pages, not just high authority domains.
- Pitching without a content fit. If your page does not answer the cited need, update it before you ask.
- Copying rival anchor text blindly. Match search intent, not just words.
- Relying on one index. Spot check with a second source or manual searches like "site:example.com your topic".
Questions
A backlink gap is the set of sites that link to your rivals but not to you. It is built by comparing referring domains or linking URLs for the same topic. For a small site, it is the fastest qualified prospect list because those sites already link to similar pages.
A backlink is a link on another site that points to your page. It acts like a citation. Good backlinks help discovery and can improve your chances to rank when the content matches the search.
Use a backlink index that offers a limited free view and enter your URL. You can also run search operators, for example your brand name in quotes, to spot unlinked mentions. Any single source will be incomplete, so combine methods.
A link gap compares who links to rivals, not what queries they rank for. Use a link gap list to plan outreach and content that earns links. Use a keyword gap to plan pages to write and internal links to add.
If devnotes.example links to a rival’s rate limit guide, email the editor of that page. Reference the sentence that links out, explain how your guide adds a clearer example, and ask for inclusion. Keep it short and specific.
Sources
Check my site, free
Run the free check on your URL and it will read your site, the searches around it and the rivals on them in about thirty seconds, and show three findings whole.
- Free check, no card
- Read-only, your own accounts
- Readable by your agent
Read next
- GuideBacklink gap: the sites that link to your rivals and not to you
- GuideHow to get backlinks for a small product site
- GuideReferring domains: what the count means and what moves it
- GuideBroken backlinks: the links you are losing to pages that are gone
- Free toolBroken link checker
- GlossaryBacklink
- GlossaryOutbound link
- GlossarySitewide link