Technology
How does a search engine work?
A search engine works by constantly crawling the web, indexing what it finds, and ranking pages to answer your queries. When you search, it doesn't scan the live web — it instantly sorts its pre-built index to surface the most relevant results.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how a search engine works.
Step by step
- 1'Crawler' bots follow links to discover web pages.
- 2It stores what it finds in a giant searchable index.
- 3When you search, it ranks indexed pages for relevance.
- 4Ranking weighs keywords, links, quality, and many other signals.
- 5It returns results in a fraction of a second.
Frequently asked questions
- How does a search engine find results so fast?
- It searches its own pre-built index of the web, not the live internet, so it just sorts already-gathered data in milliseconds.
- How does a search engine decide the order of results?
- Complex ranking algorithms weigh relevance, page quality, links, freshness, and user signals to estimate which pages best answer your query.
- What is web crawling?
- Automated bots following links from page to page to discover and revisit content, which the engine then indexes for searching.