Perplexity, ChatGPT, Google SGE: Comparing AI Search Engines for GEO
Comparative analysis of the main generative search engines. How each selects, cites and displays sources — and what it means for your GEO strategy.
The Generative Search Engine Landscape
The online search market is undergoing its greatest transformation since the emergence of Google. Several players now offer search engines powered by generative AI, each with its own approach to selecting, synthesizing and citing sources.
Understanding the specifics of each engine is essential to adapting your GEO strategy.
Google SGE (Search Generative Experience)
How It Works
Google SGE integrates generative responses directly into traditional search results. For certain queries, an AI panel appears at the top of the page, providing a summary with links to the sources used.
Source Selection
Google SGE relies on:
- The existing Google index and traditional ranking signals
- Structured data to understand content
- E-E-A-T criteria to assess reliability
- Content freshness for current topics
Key Points for GEO
- Traditional SEO remains important because SGE uses the same index
- Schema.org structured data has a direct impact
- Content already well-positioned in the SERPs has an advantage
- Rich results (featured snippets, FAQ) increase the chances of being cited
Perplexity AI
How It Works
Perplexity is a conversational search engine that provides sourced answers with numbered citations linking directly to the web pages used. It is the tool that most explicitly cites its sources.
Source Selection
Perplexity uses:
- A proprietary web crawler in addition to search results
- A semantic relevance analysis of content
- Source reliability (recognized, institutional and expert sites)
- Information freshness
Key Points for GEO
- Perplexity particularly values factual and sourced content
- Articles with numerical data are more likely to be cited
- Content structure (clear headings, lists, tables) facilitates extraction
- Being a recognized source in your niche is a major advantage
ChatGPT (with Web Browsing)
How It Works
ChatGPT, when using web browsing, performs searches to supplement its responses with current information. It synthesizes results and can cite the sources used.
Source Selection
ChatGPT with web browsing:
- Uses Bing results as its search base
- Selects pages based on their relevance to the query
- Extracts the most directly usable information
- Can access full page content for in-depth analysis
Key Points for GEO
- Optimization for Bing is important (submit your sitemap to Bing Webmaster Tools)
- Well-structured content with direct answers is favored
- Brand authority influences selection
- Long and detailed content is preferred for complex responses
Comparative Table
| Criterion | Google SGE | Perplexity | ChatGPT (web) |
|---|---|---|---|
| Index base | Google index | Own crawler + search | Bing |
| Source citation | Integrated links | Numbered citations | Contextual links |
| Importance of traditional SEO | Very high | Medium | High (Bing) |
| Structured data | High impact | Medium impact | Low impact |
| Favored content type | Rich results | Factual content | Detailed content |
| Freshness | Important | Very important | Variable |
| Market share | Dominant | Growing | Significant |
Multi-Platform Strategy
Rather than optimizing for a single AI engine, adopt a universal approach that covers the common fundamentals:
- Quality content: depth, expertise, cited sources
- Structured data: Schema.org for Article, Author, FAQ, Breadcrumb
- Broad indexation: submit your sitemap to both Google AND Bing
- Clear structure: hierarchical headings, lists, tables, summaries
- Freshness: update regularly with the most recent information
- E-E-A-T: author profiles, about page, reliable sources
Frequently Asked Questions
Which AI engine generates the most traffic?
Google SGE, due to its dominant position in search, is the most significant potential source of traffic. However, Perplexity is experiencing rapid growth and generates highly qualified traffic thanks to its direct citations.
Should you create different content for each AI engine?
No. The fundamental principles (quality, structure, sources) are shared. Focus on creating excellent, well-structured content — it will naturally be well-handled by all engines.
Will AI engines replace Google?
A complete replacement in the short term is unlikely. The most probable scenario is a coexistence where Google increasingly integrates AI (SGE) while retaining traditional results, and where alternatives like Perplexity capture a growing share of certain types of queries.
Further reading
The rise of AI engines directly impacts digital advertising: discover the best tools to save money on Google Ads and our guide to the best web analytics agencies to measure your visibility across AI platforms.
Frequently asked questions
What is the best AI search engine in 2026?
Google AI Overviews dominates by market share, ChatGPT excels at detailed conversational answers, and Perplexity stands out for citation transparency with numbered sources. The best choice depends on the use case.
How do AI search engines select their sources?
Each engine has its own criteria: Google AI Overviews favors domain authority and structured data, ChatGPT prioritizes content depth, and Perplexity places particular importance on source freshness and reliability.
Should you optimize differently for each AI engine?
The fundamentals are shared (structured content, E-E-A-T, structured data), but each platform has its specifics. An effective GEO strategy covers shared criteria while adapting certain aspects per platform.