Googlebot and Crawling: How Google Searches the Web
Googlebot is Google's automated web crawler that systematically visits web pages, reads their content, and follows links to discover and process new and updated pages for the Google index.
Key Takeaways
- ✓Googlebot is Google's primary crawler for desktop and mobile
- ✓Mobile-First Indexing means: Googlebot primarily crawls the mobile version
- ✓GPTBot traffic grew 305% in 2025 compared to the previous year
- ✓AI crawlers like GPTBot and ClaudeBot do not execute JavaScript
- ✓robots.txt controls access for different crawler types
Crawling is the first step in the search engine process. Without crawling, there's no indexing; without indexing, no ranking. In 2026, crawling is more complex than ever, as numerous AI crawlers are searching the web alongside Googlebot.
How Googlebot Works
Googlebot is an automated program that visits web pages and reads their content. It starts with known URLs, downloads the HTML code, extracts all links, and adds them to a crawling queue. This process repeats billions of times.
Googlebot exists in two variants: Desktop and Mobile. Since the complete transition to Mobile-First Indexing in 2024, the Mobile crawler is the primary version. Google evaluates websites primarily based on their mobile presentation.
Understanding Crawl Budget
Crawl budget describes how many pages Googlebot crawls on a website within a specific timeframe. It's determined by two factors: crawl rate (how quickly the server responds) and crawl demand (how important and current the content is).
For small websites with fewer than 1,000 pages, crawl budget is rarely a problem. For large websites with tens of thousands of pages, inefficient crawl budget usage can result in important pages not being indexed.
AI Crawlers: The New Dimension
Alongside Googlebot, numerous AI crawlers are searching the web in 2025/2026. GPTBot traffic grew by 305 percent compared to the previous year. Overall, crawler traffic increased by 18 percent. The most important AI crawlers are GPTBot and OAI-SearchBot (OpenAI), ClaudeBot (Anthropic), PerplexityBot (Perplexity), and Google-Extended.
A fundamental difference: AI crawlers typically don't execute JavaScript. Websites whose content is only rendered client-side are invisible to AI systems. Server-Side Rendering (SSR) is therefore mandatory.
robots.txt for Crawler Control
The robots.txt file controls which crawlers are allowed to visit which areas of the website. For SEO and GEO, a differentiated strategy is recommended: allow Googlebot and search crawlers unrestricted access, also allow AI search crawlers (OAI-SearchBot, PerplexityBot), and handle training-only crawlers (GPTBot, Google-Extended) optionally based on strategic consideration.
Important: The ChatGPT user crawler has ignored robots.txt since December 2025. Complete blocking of OpenAI crawlers is therefore no longer possible.
Data & Statistics
GPTBot-Traffic wuchs 305% gegenüber dem Vorjahr
Cloudflare (2025)Gesamter Crawler-Traffic (AI + Suche) wuchs 18% in 2025
Cloudflare (2025)“”
— Gary Illyes, Google Search Analyst