What ChatGPT says about you isn't what Claude says. Here's how to test all four—and what to do with the results.

I made a discovery that changed how I approach AI visibility.

A client came to me confident about their AI presence. "We checked—ChatGPT mentions us when you ask about our category."

So I tested Claude. Nothing.

Perplexity? They mentioned a competitor.

Gemini? Outdated information from 2022.

That's when I realized: testing one AI system tells you almost nothing. The real picture only emerges when you test across all four major LLMs—and understand why they disagree.

This guide will show you exactly how to run a comprehensive multi-LLM test, interpret the results, and use the differences to improve your visibility across all AI systems.

Why Multi-LLM Testing Matters

Each major AI system has different:

Training data and cutoff dates

  • ChatGPT and Claude have different knowledge bases

  • Perplexity actively searches the web

  • Gemini integrates with Google's index differently

Citation preferences

  • Some prioritize academic/authoritative sources

  • Some favor recent content

  • Some weight structured data more heavily

Response patterns

  • ChatGPT tends toward comprehensive lists

  • Claude often provides nuanced analysis

  • Perplexity cites sources explicitly

  • Gemini integrates with Google's knowledge graph

What this means: Being visible to one AI system doesn't mean you're visible to others. And each system reaches different users with different intent.

A comprehensive AI visibility strategy requires visibility across the full LLM landscape.

The Four Systems You Need to Test

ChatGPT (OpenAI)

Why it matters: Largest user base, most mainstream adoption. If someone asks AI for a recommendation, they're probably asking ChatGPT.

Characteristics:

  • Tends toward balanced, comprehensive responses

  • Often provides lists of options

  • Training data has specific cutoff (varies by version)

  • Won't browse web unless specifically using browsing feature

Best for queries like:

  • "What are the best tools for X?"

  • "How do I approach Y?"

  • "Explain Z to me"

Claude (Anthropic)

Why it matters: Rapidly growing, especially popular with professionals and enterprises. Known for nuanced, thoughtful responses.

Characteristics:

  • Often provides more analytical responses

  • Strong on nuanced/complex topics

  • Different training data than ChatGPT

  • May cite different sources for same query

Best for queries like:

  • "Help me think through X"

  • "What should I consider when Y?"

  • "Compare approaches to Z"

Perplexity

Why it matters: Explicitly designed for search with citations. Shows you exactly where it's pulling information from.

Characteristics:

  • Actively searches the web (not just training data)

  • Explicitly cites sources with links

  • Results change as web content changes

  • Most "real-time" of the major systems

Best for queries like:

  • "What are the latest developments in X?"

  • "Who are the leading companies in Y?"

  • "What does research say about Z?"

Gemini (Google)

Why it matters: Integrated with Google's ecosystem. May influence future search behavior and has access to Google's knowledge graph.

Characteristics:

  • Integrates with Google's index

  • Access to knowledge graph entities

  • May reflect Google Search rankings differently than others

  • Continues to evolve with Google's AI strategy

Best for queries like:

  • "What is X?"

  • "Who provides Y services?"

  • "How does Z work?"

The Complete Testing Protocol

Here's the exact process I use for multi-LLM visibility testing. Set aside 45-60 minutes for a thorough test.

Phase 1: Preparation (10 minutes)

Step 1: Define your category terms

List 3-5 ways someone might describe what you do:

  • Primary category: "AI Engine Optimization consultants"

  • Secondary category: "AI search visibility experts"

  • Related category: "AEO agencies"

  • Problem-based: "help businesses appear in ChatGPT"

  • Outcome-based: "improve AI visibility"

Step 2: Identify your top 3-5 competitors

Who should appear when someone asks about your category? List them—you'll be tracking their visibility too.

Step 3: Set up a tracking document

Create a spreadsheet with columns:

  • Query

  • ChatGPT response

  • Claude response

  • Perplexity response

  • Gemini response

  • Your mention (Y/N/Partial)

  • Competitor mentions

  • Notes

Phase 2: Category Queries (15 minutes)

Test how AI systems describe your entire category.

Query Set 1: Category Discovery

Ask each of the four AI systems:

"What companies provide [your primary category]?"

"Who are the leading [your category] providers?"

"What should I look for in a [your category]?"

Document for each response:

  • Are you mentioned?

  • What position? (First, middle, end of list?)

  • Are competitors mentioned?

  • What attributes are highlighted?

  • How is the category defined?

Query Set 2: Problem-Based Discovery

"How can I [solve the problem you solve]?"

"My company is struggling with [problem you solve]. What should I do?"

"What's the best way to [achieve outcome you deliver]?"

Document for each:

  • Are solutions like yours recommended?

  • Are specific providers named?

  • What approach is suggested?

Phase 3: Direct Brand Queries (15 minutes)

Test what AI systems know about your company specifically.

Query Set 3: Brand Knowledge

Ask each system:

"What does [your company name] do?"

"What is [your company name] known for?"

"Tell me about [your company name]"

Document for each:

  • Does the AI know you exist?

  • Is the information accurate?

  • Is it current or outdated?

  • What sources seem to inform the response?

Query Set 4: Brand + Category

"How does [your company] compare to other [category] providers?"

"Is [your company] a good choice for [your service]?"

"What do people say about [your company]?"

Document for each:

  • Are you positioned accurately?

  • What differentiators are mentioned?

  • Any inaccuracies to correct?

Phase 4: Comparison Queries (15 minutes)

Test how you're positioned against competitors.

Query Set 5: Direct Comparisons

"[Your company] vs [Competitor]—which should I choose?"

"What's the difference between [your company] and [competitor]?"

"Comparing [your company] and [competitor] for [use case]"

Document for each:

  • Are you accurately represented?

  • What differentiators are highlighted?

  • Is the comparison fair?

  • What's missing?

Query Set 6: Best-For Scenarios

"Which [category] is best for [your ideal customer type]?"

"What [category] solution works best for [specific use case]?"

"I'm a [your target persona]—what [category] should I use?"

Document for each:

  • Are you mentioned for your ideal scenarios?

  • Are competitors mentioned for scenarios they don't serve well?

  • Opportunities to better position for specific use cases?

Interpreting Your Results

After completing the protocol, you'll have a matrix of responses. Here's how to analyze it:

Pattern 1: Consistent Visibility

You appear across all four systems for category queries.

This is the goal state. Your foundation is strong.

Next steps:

  • Optimize for positioning (first mention vs. last)

  • Improve how you're described (accuracy, differentiators)

  • Monitor for changes

Pattern 2: Partial Visibility

You appear in some systems but not others.

This is most common. It reveals specific gaps.

If you're missing from ChatGPT:

  • Check if your content is structured for extraction

  • Verify you're not blocking OpenAI crawlers

  • Your content may lack citable statements ChatGPT prefers

If you're missing from Claude:

  • Claude may weight different authority signals

  • Check your expertise/credential signals

  • Review content depth and nuance

If you're missing from Perplexity:

  • Your web content isn't ranking/visible

  • Check technical SEO fundamentals

  • Verify content is being indexed

If you're missing from Gemini:

  • Google Knowledge Graph may not recognize your entity

  • Check your Google Business presence

  • Verify schema markup

Pattern 3: Invisible

You don't appear in any system for category queries.

This requires foundational work.

Immediate priorities:

  1. Verify AI crawlers can access your content

  2. Add explicit definitions of what you do

  3. Build citable, factual content

  4. Strengthen authority signals

Pattern 4: Misrepresented

You appear, but information is wrong or outdated.

This is actually good news—it means you're visible enough to be mentioned.

Correction strategy:

  1. Identify the incorrect information

  2. Find where AI might have gotten it (old pages, third-party sites)

  3. Update your own content with correct, prominent information

  4. Wait for systems to re-train or re-crawl

  5. For Perplexity, correct information may update faster

Pattern 5: Competitor-Dominated

Competitors appear consistently; you don't.

This reveals specific competitive disadvantages.

Analysis questions:

  • What content do competitors have that you don't?

  • How is their content structured differently?

  • What authority signals do they have?

  • What categories are they owning?

The Difference Analysis

Here's the most valuable part of multi-LLM testing: understanding WHY systems respond differently.

When ChatGPT Includes You But Claude Doesn't:

Possible causes:

  • Different training data emphasis

  • ChatGPT may have crawled pages Claude missed

  • Claude may have different authority thresholds

  • Content structure may match ChatGPT's extraction patterns better

Action: Look at what content ChatGPT seems to cite. Ensure similar depth/structure across your site so Claude picks it up too.

When Perplexity Includes You But Others Don't:

Possible causes:

  • Your recent content is strong (Perplexity crawls live web)

  • Other systems have outdated training data

  • Your SEO is working but content isn't in training data

Action: This is actually positive—maintain your web presence. Older systems will catch up as they retrain. Focus on building more linkable, authoritative content.

When Gemini Includes You But Others Don't:

Possible causes:

  • Google Knowledge Graph recognizes your entity

  • Your Google Business presence is strong

  • You may have schema markup others don't parse

Action: Double down on structured data. Ensure your entity definition is clear. Other systems may begin to recognize these signals too.

When Others Include You But Perplexity Doesn't:

Possible causes:

  • Your live web content may have issues

  • Recent competitors may have overtaken you

  • Technical SEO problems

Action: Perplexity reflects current web state. Fix any technical issues and ensure your best content is prominent and crawlable.

Building Your Multi-LLM Action Plan

Based on your results, prioritize actions:

Priority 1: Technical Access (Invisible on all)

If no AI system mentions you:

Week 1:

  • Check robots.txt for AI crawler blocks

  • Verify JavaScript rendering isn't hiding content

  • Ensure basic SEO allows crawling/indexing

Week 2:

  • Add explicit entity definition to homepage

  • Create structured content with citable facts

  • Publish "What is [your service]?" content

Priority 2: Content Gaps (Partial visibility)

If you appear on some systems but not others:

Week 1:

  • Analyze what content successful mentions cite

  • Identify structural patterns in that content

  • Map gaps between visible and invisible content

Week 2-3:

  • Restructure key pages with citable elements

  • Add definition blocks, statistics, comparisons

  • Strengthen authority signals (bios, credentials, evidence)

Priority 3: Positioning (Visible but poorly positioned)

If you appear but not prominently or accurately:

Week 1:

  • Document exactly how you're described

  • Identify inaccuracies or missed differentiators

  • Find source of incorrect information

Week 2-3:

  • Update content to emphasize correct positioning

  • Add comparison content showing differentiators

  • Create content addressing specific use cases

Priority 4: Competitive Response (Competitors dominating)

If competitors appear and you don't:

Week 1:

  • Analyze competitor content structure

  • Identify their citation-worthy elements

  • Map their authority signals

Week 2-4:

  • Create content that matches or exceeds their depth

  • Build authority signals in your space

  • Target specific queries they're winning

Ongoing Monitoring Protocol

Multi-LLM testing isn't a one-time activity. Set up regular monitoring:

Weekly (5 minutes):

  • Test one category query across all four systems

  • Note any changes in your visibility

  • Track new competitor mentions

Monthly (30 minutes):

  • Run full protocol for priority queries

  • Document trends over time

  • Identify new queries to target

Quarterly (60 minutes):

  • Complete comprehensive test

  • Analyze changes since last quarter

  • Adjust strategy based on patterns

The Multi-LLM Advantage

Most businesses either:

  1. Don't test AI visibility at all

  2. Test only ChatGPT and assume it represents everything

You now have a systematic approach to understanding your visibility across the entire AI landscape.

This matters because:

  • Different users prefer different AI systems

  • Different AI systems reach users with different intent

  • Visibility gaps on one system are often fixable

  • Cross-system consistency signals strong fundamentals

The businesses winning AI search are the ones treating it as a multi-platform challenge—just like they once treated multi-channel marketing.

What I've Learned from Hundreds of Tests

After running this protocol on hundreds of B2B websites, patterns emerge:

Average first-test results:

  • 12% appear on all four systems

  • 34% appear on two or three

  • 31% appear on only one

  • 23% appear on none

Most common gaps:

  • Perplexity visibility without ChatGPT/Claude (good SEO, weak content structure)

  • ChatGPT visibility without Claude (content structure works for one but not both)

  • Complete invisibility (fundamental technical or content issues)

Fastest improvements come from:

  1. Fixing technical blocking issues (immediate impact on Perplexity)

  2. Adding structured definitions (improves all systems)

  3. Building citable statistics (improves citation likelihood everywhere)

The AI search landscape is fragmented. Users are spread across systems. Your visibility strategy needs to account for all of them.

Start with the test. Understand your baseline. Then systematically close the gaps.

Want a professional multi-LLM assessment? Our AI Visibility Audit tests your presence across all four systems with 47 standardized queries, analyzes the differences, and delivers a prioritized roadmap for cross-platform visibility.

Elizabeta Kuzevska is the Co — Founder of Revenue Experts AI, building AI Revenue Intelligence Systems powered by 100+ specialized agents. Her methodology integrates multi-agent architectures with human expertise to transform how B2B companies generate revenue. See the courses and try some agents

Connect on x: @ekuzevska

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