Definition
Log file analysis is reviewing server access logs to see which URLs search engine and AI crawlers request, how often, and what responses they get.
Log file analysis explained
Every request to your server is recorded in an access log with the time, URL, status code and user agent. Filtering those logs for crawlers such as Googlebot, Bingbot, OAI-SearchBot, PerplexityBot and ClaudeBot shows real crawler behavior, rather than what a crawl tool simulates.
Log analysis can reveal:
- Important pages that crawlers rarely or never visit.
- Crawl effort wasted on parameters, filters, redirects or errors.
- Whether AI crawlers are reaching your site at all, or being blocked with 403 errors.
- How quickly new pages are discovered after publishing.
- Fake bots pretending to be Googlebot, which you can check against published IP ranges.
Logs can be large and sometimes live with your hosting provider or CDN, so it helps to agree access early. Even a sample of a few weeks is usually enough to spot the main patterns.
Example
You're unsure whether ChatGPT can read your site. Your server logs show OAI-SearchBot requesting your pages, but every request receives a 403 from your CDN's bot rules. Log file analysis found a problem no content change would have fixed.
Why it matters
Logs are the only direct evidence of how crawlers treat your site, which makes them invaluable for large sites and AI crawler checks.
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Related terms
- Crawl budgetCrawl budget is the number of URLs a search engine can and wants to crawl on a site in a given time, set by crawl capacity and crawl demand.
- AI crawlerAn AI crawler is an automated bot run by an AI company that fetches web pages to train models, to build a search index, or to answer a user's question.
- CrawlingCrawling is the process by which search engine and AI bots discover web pages by following links and sitemaps, then download their content for processing.
- OAI-SearchBotOAI-SearchBot is OpenAI's crawler for surfacing websites in ChatGPT search, and blocking it keeps your pages out of ChatGPT search answers.