ChatGPT, Perplexity, or Gemini: <blue>Where Should Your AEO Efforts Focus?</blue>

For most brands, the answer is not to choose one. Focus your AEO effort on the questions buyers ask right before they spend money, publish answers every engine can retrieve, and then use per-platform tracking to decide where extra work pays off. ChatGPT, Perplexity, and Gemini differ in reach and in how visibly they cite sources, but those differences should change how you prioritize and measure, not what good content looks like.

Key takeaways

• ChatGPT, Perplexity, and Google's AI features all draw on live web results for many questions, so one well-structured answer page can earn visibility in more than one of them.
• ChatGPT and Google's AI surfaces each report audiences near or above 1 billion users. Perplexity shows numbered citations in every answer, which makes it easier to trace which page earned the mention.
• For Google's AI Overviews and AI Mode, Google says no special optimization is required beyond being indexed and eligible for a snippet. SEO fundamentals are the entry ticket.
• Choose prompts before platforms, then track every engine weekly.

Why is "which AI platform?" the wrong first question?

Platform choice matters less than prompt choice. A brand that wins the questions buyers ask before a purchase will usually show up across several engines, while a brand that tunes content for one engine's quirks can still miss the questions that drive revenue.

That is why the answer engine optimization services Onward runs begin with a prompt set, not a platform list. The prompt set defines what winning means: being named, cited, or recommended when a buyer asks a question with real purchase intent. Platform tracking comes second: it shows where those answers appear and how often you are in them.

Single-platform tactics also age quickly. AI assistants change features, partners, and interfaces often, while a page that clearly answers a buyer's question keeps its value.

How do ChatGPT, Perplexity, and Gemini differ for AEO?

The details below come from each company's own documentation and disclosures as of October 2026.

ChatGPT: the largest single audience

ChatGPT is the reach play. OpenAI's DevDay 2026 recap, published September 29, 2026, refers to ChatGPT's "1.2B weekly users." According to OpenAI's help center, ChatGPT may search the web automatically when a question benefits from current information, sometimes rewrites the question into targeted queries sent to partner search providers, and may include citations in the response.

OpenAI says a site should allow its OAI-SearchBot crawler to be eligible for inclusion in search results, and that placement is not guaranteed. ChatGPT answers can combine retrieved pages with what the model already understands about a brand. Consistent descriptions of who you are, what you offer, and where you operate make that understanding more accurate.

Perplexity: citations you can see and trace

Perplexity is built around sourcing. Its help center says it searches the internet in real time and that each answer includes numbered citations linking to the original sources. For a marketer, that makes Perplexity the easiest engine to diagnose: you can see which page earned the mention and which competitor pages were cited alongside it.

Visible citations also mean a single page can send a buyer straight to you. In Onward's Villa Alberti program, a guest asked Perplexity where to stay near Las Catalinas on August 12 and was pointed to a comparison article the villa had published in May. That inquiry became more than $100,000 in booked revenue, one result documented in the Villa Alberti AEO case study.

Gemini and Google's AI surfaces: scale built on Search

Google's AI footprint is large and spread across several products. On Alphabet's Q2 2026 earnings call on July 22, 2026, Sundar Pichai said the Gemini app has 950 million monthly active users and that AI Mode has passed 1 billion monthly active users.

For AI Overviews and AI Mode, Google's Search Central documentation is unusually direct: a page must be indexed and eligible to appear in Search with a snippet, and there are no additional requirements or special optimizations needed. Google also notes these features may use "query fan-out," running several related searches across subtopics to build one response. In practice, that rewards sites with a clear page for each subtopic a buyer might ask about. It also means AEO for Google starts with technical and content SEO, which is why Onward plans for combining SEO, AEO, and GEO in one program rather than as separate projects.

How should you decide where to focus first?

Use this sequence.

1. Build the prompt set. List the questions a buyer asks before purchasing: head-to-head comparisons, "best option for" questions, pricing and logistics questions. Rank them by buying intent, not search volume.
2. Test each prompt on each engine. Record whether you are named, cited, or absent, and which sources are cited instead. The baseline shows where your visibility gaps sit on each platform.
3. Fix the shared foundations once. Confirm that robots.txt and your CDN are not blocking OAI-SearchBot or Googlebot, that key pages are indexed, and that each priority question has one page that answers it in the first two sentences. The AEO/GEO checklist covers the full technical list.
4. Weight effort by business model. If your buyers compare options before a large purchase, comparison pages and proof pages do the most work, and a citation-first engine like Perplexity makes their impact easy to trace. If you sell at volume to consumers, Google's AI surfaces and ChatGPT carry the reach.
5. Measure weekly and reallocate. Track the same prompts on every platform you care about, then put the next month of content toward the engines and questions where you are closest to being named.

What does per-platform measurement look like in practice?

Per-platform measurement means running a fixed prompt set against each engine on a schedule and recording presence, position, and sentiment. The result is a visibility rate per platform, so the focus decision rests on data.

Villa Alberti, a luxury rental in Costa Rica, is a useful reference. Onward tracked 58 booking-intent prompts weekly across seven AI platforms, including ChatGPT, Perplexity, Gemini, Google AI Mode, and Google AI Overviews. Its overall AI visibility climbed from 0.83% during a February baseline period to 12.86% by early September, roughly 15x, after about 60 articles that each answered one buyer question directly.

The most useful finding for this decision: the villa's presence was spread across platforms rather than concentrated in one source. The same answer-first articles earned mentions in several engines at once, which is a strong argument for a prompt-first strategy over a platform-first one.

Visibility is only the first layer. The commercial question is whether AI-referred visitors become customers or bookings, which requires connecting AI traffic to backend outcomes through full-funnel measurement and dashboards. Without that connection, a rising visibility score is encouraging but not yet a business case.

Do you need separate content for each AI platform?

Usually not. ChatGPT, Perplexity, and Google's AI surfaces all tend to reward pages that answer a specific question clearly, back it with verifiable facts, and are easy for crawlers to access. Platform-specific work tends to be technical, such as crawler permissions or Google indexing, rather than editorial.

The bottom line

Start where your revenue is decided: the questions buyers ask before they commit. Build one strong answer per question, make sure every major engine can reach it, and let weekly per-platform tracking tell you where to push next. ChatGPT gives you reach, Perplexity gives you traceable citations, and Google's AI surfaces reward the SEO work you may already be doing.

To find out how your brand shows up today, schedule a free audit. Onward's AEO audit tracks a prompt set across eight AI platforms, from ChatGPT to Google AI Mode, and you leave with the tracked prompts and your current rank, with no obligation.