The essentials
- Definition: share of voice measures the proportion of a market's visibility a brand occupies, against all its competitors.
- Calculation: the brand's visibility divided by the total visibility of the competitive set, over a defined scope of queries, keywords or questions.
- New in 2026: share of voice is now also measured in AI assistants' answers, by counting each brand's citations across a set of questions.
- Why it matters: it is a relative metric; visibility holding steady while competitors advance is a loss that rank tracking doesn't show.
The aim of Share of voice (SOV) measures the portion of a market's visibility a brand occupies, relative to the total visibility of the competitive set. It comes from mass advertising, where it meant an advertiser's share of media spend in its sector, and has spread to every digital channel: search, online advertising, social media, and since 2025 AI assistants' answers. Its value lies in being relative: unlike a traffic volume or an average position, it tells you how a brand's place is changing compared with everyone else's.
The calculation by channel
| Channel | Formula | Source |
|---|---|---|
| SEO | The sum of the brand's impressions or estimated traffic / the total for the tracked keyword basket across all competitors | Search Console, a rank tracking tool |
| Search advertising | Impression share: impressions won / eligible impressions | Google Ads, a native metric |
| Social networks | Brand mentions / mentions of all tracked brands | A social listening tool |
| AI engines | Questions where the brand is cited / total questions tested | Manual readings or a GEO tracking tool |
| Display and video advertising | The brand's spend / total sector spend | Sector estimates |
Google Ads' impression share is the only share of voice supplied directly by a platform; it also shows the share lost to budget and the share lost to rank, which points to the lever to pull. The other channels require you to define the scope yourself: a keyword basket, a competitor list, a set of questions.
Share of voice in AI engines
This is the fastest-growing use. The principle is to fix a list of shortlisting questions the sector's buyers ask ("which solution for this need", "best agency for this service in this place"), put them regularly to several assistants, and count how many times each brand is cited. A 30% share of voice means the brand appears in three answers out of ten. The measurement demands repetition, since answers vary from one run to the next: three readings per question per assistant is the minimum. The full method is described in monitoring your brand's presence in generative AI, and the associated metrics in GEO KPIs.
Why this metric complements the others
- It reveals relative losses: steady traffic while the market grows 20% is a decline, invisible in a traffic report.
- It gives positions a context: moving from 4th to 3rd has little effect if three competitors also occupy the rich results; classic tracking is presented in tracking your SEO rankings.
- It steers budget: impression share lost to budget flags a channel where spending more would pay; lost to rank, it flags a quality or bidding problem.
- It measures awareness: correlated with brand search volume, it is one of the few quantified metrics for awareness work.
- It speaks to a leadership team: "we hold 18% of the market's visibility against the leader's 31%" is understood immediately.
Measurement precautions
- Define the scope and leave it alone: adding keywords or competitors along the way makes the series incomparable.
- Choose the right competitors: those that actually appear on the queries you target, not your traditional commercial rivals; on informational queries they are often media outlets and directories.
- Separate brand from the rest: queries containing the company name inflate share of voice artificially and should be excluded from the acquisition basket.
- Be wary of estimates: traffic estimated by third-party tools carries a wide margin of error; the trend counts for more than the absolute value.
- Read it quarterly: monthly variation mostly reflects algorithm noise; share of voice is a long-trend metric, as visibility in generative AI.
How GreenRed helps
Rather than juggling several tools, GreenRed's GEO tracking brings these metrics together in a single dashboard, compares them over time and tells you which actions come first. You can try it free, with no card, from the Pricing.
Frequently asked questions
What is share of voice?
The share of a market's visibility a brand occupies, relative to the total visibility of the competitive set. It is calculated over a defined scope of keywords, mentions or questions, and applies to search, advertising, social media and AI assistants' answers.
How do you calculate share of voice in SEO?
By dividing the brand's impressions or estimated traffic by the total obtained by all tracked competitors on the same keyword basket. The basket and the competitor list must be fixed so successive readings stay comparable.
How do you measure share of voice in ChatGPT or Perplexity?
By fixing a list of the sector's shortlisting questions, putting them regularly to several assistants and counting the questions where the brand is cited. Since answers vary from one run to the next, you need at least three readings per question per assistant.
How does it differ from rank tracking?
Rank tracking measures your position in isolation; share of voice relates it to your competitors'. Steady traffic while the market advances is a decline only the second reveals. The two are read together, share of voice quarterly.