What is share of voice in AI search?
Share of voice in AI search is your brand’s portion of the brands an assistant names for a fixed set of prompts. It counts appearances, whether or not the answer links to you. It is a competitive comparison, and it is not the same metric as citation share.
Why it matters for AI visibility
Buyers often remember who was recommended, not which URL sat under the sentence. Share of voice captures that named presence relative to competitors you choose. It matters because a brand can be the most mentioned name and still not own the citations, or the reverse. The comparison is only fair when every brand is counted with the same rules: exact name and obvious variants, same prompts, same engines, and a note when an answer lists five brands versus one. Do not average engines into a single percentage unless you also show the split. An assistant that names you warmly in one engine and ignores you in another is a different problem from a uniform gap. Use the metric to decide where to read answers, not as a rank the engines themselves award.
Example
Ten tracked prompts on one engine name your brand in four answers and a named rival in six. Your share of voice against that rival, on mentions, is four of the ten brand appearances you agreed to count. If the rules ignore a third brand, say so in the report.
Related terms
Citation share uses cited URLs as the denominator. Brand mentions in LLMs are the raw appearances share of voice summarizes. LLM visibility is the wider question of whether you show up at all. Label the denominator every time you report a share.