GEO & AI Search

Timeline: How Search Changed from 2020 to 2025

2025-11-25 Arun Nagarathanam

Quick Answer

From 2020 to 2025, search transformed from a link-based discovery system to an AI-powered answer engine. Key milestones: Google's passage indexing (2020), ChatGPT's launch (2022), AI Overviews rollout (2024), and the emergence of GEO as a discipline (2024-2025). Understanding this timeline helps you see where search is heading next.

Five years doesn't sound like a long time.

But search in 2025 is almost unrecognizable from search in 2020.

Here's exactly how we got here, year by year.

Search Evolution at a Glance

2020

Peak Traditional SEO

Passage indexing • Core Web Vitals • GPT-3 released (research only)

2021

AI Foundations

MUM announced • Entity optimization grows • Zero-click hits 65%

2022

ChatGPT Launches

100M users in 60 days • Fastest consumer adoption ever • Industry dismisses it

2023

The AI Race Begins

Bing + AI • Google SGE • GPT-4 • Perplexity gains traction

2024

Mass Adoption

AI Overviews rollout • Gartner predicts 25% drop • GEO emerges as discipline

2025

The New Normal

AI search is mainstream • Multi-platform optimization required • GEO is essential

  • 2020

    Peak Traditional SEO

    Passage indexing • Core Web Vitals • GPT-3 released (research only)

  • 2021

    AI Foundations

    MUM announced • Entity optimization grows • Zero-click hits 65%

  • 2022

    ChatGPT Launches

    100M users in 60 days • Fastest consumer adoption ever • Industry dismisses it

  • 2023

    The AI Race Begins

    Bing + AI • Google SGE • GPT-4 • Perplexity gains traction

  • 2024

    Mass Adoption

    AI Overviews rollout • Gartner predicts 25% drop • GEO emerges as discipline

  • 2025

    The New Normal

    AI search is mainstream • Multi-platform optimization required • GEO is essential

2020

The Before

The Peak of Traditional SEO

The world: COVID-19 drives massive online adoption. Businesses rush to digital.

Key Developments:

  • Google Passage Indexing - Google starts ranking specific passages, not just pages
  • Core Web Vitals announced - Page experience becomes official ranking factor
  • Featured snippets mature - Position #0 becomes highly coveted
  • GPT-3 released - OpenAI's model shows language AI potential (but no consumer product yet)

SEO focus: Content quality, backlinks, technical optimization. The 10-blue-links era is strong but showing cracks.

2021

Foundations

Google Strengthens AI Foundations

The world: Pandemic continues. Digital becomes permanent, not temporary.

Key Developments:

  • MUM (Multitask Unified Model) - Google announces 1000x more powerful than BERT
  • Core Web Vitals go live - Page experience officially affects rankings
  • Google Knowledge Panels expand - Entity-based search grows
  • Zero-click searches hit 65% - Most searches don't result in website clicks

SEO focus: Entity optimization gains attention. Some forward-thinking SEOs start discussing "entity-first" strategies.

2022

The Shift

ChatGPT Changes Everything

The world: OpenAI releases ChatGPT on November 30, 2022. Everything changes.

Key Developments:

  • ChatGPT launches (Nov 30) - Reaches 1 million users in 5 days, 100 million in 2 months
  • Google Helpful Content Update - Targets AI-generated spam (ironic timing)
  • E-E-A-T emphasis - Google adds "Experience" to E-A-T framework
  • First "AI search" conversations - Industry starts discussing AI impact on SEO

The turning point: For the first time, users could ask natural questions and get coherent, helpful answers without clicking through to websites.

SEO focus: Most SEOs dismiss ChatGPT as novelty. "It makes things up." "Users want real sources." This dismissal costs 12+ months of preparation time.

2023

The Race

The AI Search Arms Race Begins

The world: Google declares "Code Red" internally. The search industry realizes AI is not a fad.

Key Developments:

  • Microsoft Bing + ChatGPT (Feb) - First major search engine with AI chat integration
  • Google Bard launches (March) - Google's rushed AI response
  • SGE (Search Generative Experience) announced (May) - Google's AI-powered search results in testing
  • GPT-4 released (March) - Major accuracy improvement over GPT-3.5
  • Perplexity gains traction - AI-first search engine starts attracting users
  • Claude released - Anthropic enters the chat

SEO focus: "Answer Engine Optimization" (AEO) term gains traction. Some SEOs start optimizing for featured snippets more aggressively.

2024

Mass Adoption

AI Search Goes Mainstream

The world: AI search stops being experimental. It becomes the default experience.

Key Developments:

  • Google AI Overviews (May) - SGE rebranded and rolled out to all US users
  • Gartner predicts 25% search decline by 2026 (Feb) - Major analyst firm validates the shift
  • ChatGPT hits 200M weekly users - Larger than many countries' populations
  • Perplexity valued at $9B - AI-first search is a real category
  • "GEO" term emerges - Generative Engine Optimization becomes distinct from AEO (see our complete comparison)
  • Organic traffic declines measured - 15-25% drops documented across industries

The wake-up call: SEO professionals finally see traffic declines in their own data. Denial becomes impossible.

Google AI Overview showing synthesized answers at the top of search results in 2024
Google AI Overviews became the default experience for nearly half of all searches in 2024.

SEO focus: Panic gives way to adaptation. First GEO frameworks emerge. Entity optimization becomes urgent.

2025

The Present

The New Normal

The world: AI search is no longer "the future." It's the present reality.

Current State:

  • AI Overviews in 47%+ of Google searches - Nearly half of all searches show AI answers
  • LLM referral traffic up 527% YoY - New traffic source is significant
  • GEO established as discipline - Distinct from SEO and AEO
  • Multi-platform optimization required - Google, ChatGPT, Perplexity, Claude all matter
  • Entity establishment is critical - Wikidata, Knowledge Graph, schema essential
Microsoft Copilot providing AI-generated answers, demonstrating the multi-platform nature of AI search in 2025
In 2025, users search across multiple AI platforms—Google, ChatGPT, Perplexity, and Copilot all matter.

SEO focus: Integration of traditional SEO with GEO. Focus on being cited, not just ranked. Quality over quantity becomes essential, not optional.

What This Timeline Teaches Us

Five Key Lessons

  • 1. The shift happened faster than expected. From ChatGPT launch to mainstream AI search was just 18 months.
  • 2. Google adopted AI search, not fought it. The biggest search engine is now the biggest AI search provider.
  • 3. Early adapters had advantages. Those who started GEO in 2023 are now established. Late starters are playing catch-up.
  • 4. The trajectory is clear. AI search share is growing, traditional search is declining. This trend won't reverse.
  • 5. Adaptation is still possible. We're still early. There's time to learn GEO, but the window is closing.

AI Search Adoption Trajectory

Category % of Searches with AI Answers
2020 0
2021 0
2022 5
2023 25
2024 47
2025 65

Source: Industry estimates based on Gartner, SEJ, and Semrush data

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