Understand

See the citation gaps AI engines fill with competitors

See which third-party domains AI engines cite for your competitors but never for you, ranked by how much each one is worth closing.

  • Reads the domains engines cite for your category
  • A ranked list of gaps worth closing
  • Built from real scanned answers

The problem

AI trusts a handful of sources. Most brands are in none of them.

Every answer is built from pages the engine already trusts: review platforms, directories, reference sites, community threads. When those pages cover your competitors and not you, the engine has no evidence to recommend you with. The gap list shows exactly which domains are missing you, ranked by the opportunity each one represents.

900M

weekly active ChatGPT users shaped by the sources it cites

Source: OpenAI, 2026

How it works

  1. 01

    Collect the cited domains

    Every scanned answer records the third-party pages the engine cited to support what it said.

  2. 02

    Compare against competitors

    Domains that cite your rivals but never you become a ranked gap list rather than a hunch.

  3. 03

    Work the ranked list

    Gaps are ordered by opportunity, so the top of the list is the one worth closing first.

Inside the product

What you get

Cited-domain extraction

Every third-party page the engines cited on your tracked prompts is collected automatically.

Gap detection

Domains citing your rivals but never you are isolated, instead of buried in one long source list.

Opportunity ranking

Gaps are ordered by how much each one is worth closing, so the list works like a queue.

Prompt-level drill-down

See the exact pages cited for a single prompt, in the order the engine cited them.

Evidence kept

The answer text behind every gap is stored, so the recommendation is verifiable later.

What makes it trustworthy

Built from real answers

The list comes from sources engines actually cited, not from a generic domain authority index.

Ranked by opportunity

Each gap carries a rank, which turns the list into a queue instead of a wall.

Down to the prompt

You can see the exact pages cited for a single tracked prompt, in the order they were cited.

Your buyers already ask these three engines. The only question is whose name comes back.

ChatGPT

900M

weekly active users

The default first stop when buyers research software.

OpenAI, 2026
Gemini

900M

monthly active app users

Plus AI answers inside Google Search itself, in front of every searcher.

Momentic, 2026
Claude

245M

monthly active users

Its share of AI referrals to B2B sites jumped from 1.4% to 18.5% in eight months.

Stackmatix, 2026
Built for early-stage foundersWeekly scans on all three engines5 review platforms checkedProof at every stage: published, indexed, cited

Example walkthrough

How it plays out

  1. 01 · Before

    G2, Capterra, and Reddit threads were cited for four competitors on Vellum HR's top prompt — never for Vellum HR.

  2. 02 · The move

    The gap list ranked Capterra as the highest-opportunity miss and showed the exact category page being cited.

  3. 03 · After

    Outreach and a comparison page targeted that specific gap instead of a generic link-building spray.

An illustrative example using the sample Vellum HR workspace.

Questions

What is a citation gap?
A site AI engines trust and cite when recommending your category, that currently has nothing to say about you.
Which sites usually show up?
Review platforms, directories, reference sites, and community threads, in proportions that depend on your category.
What do I do about a gap?
Either earn a mention on that site or publish something it would cite. Agentic link building drafts the outreach for the first path.
Does closing a gap guarantee a mention?
No. It improves the evidence available to the engine. Whether the answer actually changes is what the prove step measures.

The brands AI trusts today are the defaults it cites for years.

Find the prompts where AI sends your buyers to a rival, and close the gap before the answer sets.

ChatGPTClaudeGemini

No credit card.