When AI generates an answer, it often points to external links to support what it says. These are called sources, and they matter because they reveal which domains the AI trusts enough to surface to users.
Not all sources are the same. In AI search, you’ll usually see them appear in two main ways: inline sources and cited sources. Together, they make up what we call source mentions, and they’re a critical part of measuring performance in Answer Engine Optimization (AEO).
1. Inline Sources
Inline sources are links embedded directly in the text of the AI’s answer. They might look like:
“According to G2…” (with a hyperlink on G2).
A phrase like “customer reviews” linked to a marketplace site.
Inline links are designed to be clicked. They guide the reader mid-sentence, often at the exact moment a claim is made. They also show which sites the AI considers useful for supporting a point.
2. Cited Sources
Cited sources appear at the bottom of an AI search result, usually as a list of references or footnotes. Examples include:
A link to a brand’s blog post.
A publisher article.
A review site or directory.
Citations act as the AI’s “evidence.” They’re less about directing the flow of reading and more about attributing where the information came from.
Why Sources Matter in AEO
Both inline and cited sources shape performance in AI search:
Presence — Did your domain appear as a source at all?
Position — Were you one of the first links, or buried lower down?
Placement — Were you linked inline to support a main point, or listed among many at the bottom?
Perception — Were you cited alongside respected publishers, or grouped with weaker references?
Inline sources influence trust in the flow of the answer. Cited sources influence credibility at the end of the answer. Both are signals of authority, but they serve different purposes.
Putting It Together
When you evaluate sources in AI search, you’re not just counting links. You’re asking what role those links play: guiding clicks mid-sentence or grounding the answer as a whole.
That’s why inline and cited sources matter differently, but together they provide the clearest picture of which domains the AI leans on, and how it presents authority to users.