SEO has moved from stuffing pages with keywords in the 1990s, to earning links after Google launched in 1998, to understanding meaning, mobile and page experience in the 2010s. Since 2022, AI assistants and Google's AI Overviews answer many questions directly, so being the clear, trusted source now matters as much as ranking.
A brief history of SEO: from blue links to AI answers
1990s: directories and keywords
The first search engines, such as AltaVista, Lycos and Excite, and directories like Yahoo ranked pages largely on the words they contained. That made it easy to rank by repeating keywords and hiding text, and results were often poor.
1998: Google and links
Google launched in 1998 with PageRank, which treated links from other sites as votes of confidence. Rankings started to depend on what the rest of the web said about a page, not just what the page said about itself. Link building became the centre of SEO, and so did link spam.
2003 to 2012: Google fights spam
Updates such as Florida (2003), Panda (2011, targeting thin and low-quality content) and Penguin (2012, targeting manipulative links) punished the shortcuts that had worked before. The lesson was lasting: write useful content and earn real links.
2011 to 2013: entities and meaning
Schema.org was launched in 2011 by the major search engines as a shared vocabulary for structured data. Google's Knowledge Graph followed in 2012, and the Hummingbird update in 2013 shifted search towards understanding the meaning of a query rather than matching words. Search engines started thinking in things, not strings.
2014 to 2019: mobile and answers
Featured snippets put direct answers at the top of results. Google's 2015 mobile-friendly update and later mobile-first indexing made the mobile version of a site the one that counts. Machine learning arrived with RankBrain in 2015 and BERT in 2019, helping Google understand natural language.
2020 to 2022: experience and helpfulness
Core Web Vitals made real-world speed and stability a ranking consideration, and the helpful content update in 2022 targeted pages written for search engines rather than people. E-E-A-T became the shorthand for content that shows real experience and can be trusted.
2022 onwards: AI answers
ChatGPT launched in November 2022, and people began asking AI assistants for recommendations instead of searching. Google introduced AI Overviews in 2024, summarising answers above the traditional results. A page can now be read and quoted without being clicked, so being the clear, trusted source matters as much as ranking.
What has stayed the same
Every major change has rewarded the same things: a site search engines can crawl and understand, content that genuinely answers people's questions, and signals from elsewhere on the web that you can be trusted. The shortcuts change; the foundation doesn't.
What it means for your website now
- SEO keeps your pages crawlable, indexed and ranking.
- AEO makes your content the clear answer that AI Overviews and assistants quote.
- GEO makes your brand consistent and credible enough to be named in AI answers.
The same work supports all three, as the complete guide to technical SEO, AEO and GEO explains.
When did SEO start?
SEO began in the mid-1990s, when website owners first tried to influence how the early search engines and directories ranked their pages.
What was the biggest change in SEO history?
Google's use of links as votes in 1998 changed SEO most, followed by the shift since 2022 to AI-generated answers that can quote a page without a click.
Is SEO still relevant with AI search?
Yes. AI search tools rely on pages they can find, read and trust, so the fundamentals of SEO are what make AEO and GEO possible.