Log file analysis examines server request records to understand how verified crawlers access URLs during a defined observation window.
What Log File Analysis means
Logs report requests that reached the server; they do not directly show indexing, rankings, or every rendering decision. Bot identification and retention limits must be considered.
Log file analysis examines server request records to see how crawlers actually access URLs, revealing observed crawl paths, response codes, and wasted requests within the available log window.
A practical inspection workflow
Obtain a bounded log period, parse timestamps, URLs, status codes, user agents, and bytes, then normalize query parameters and separate verified crawler traffic from ordinary requests.
What to verify
Compare crawler-request patterns with canonical URL inventory, sitemaps, internal links, and server responses. Sample raw entries before making a large conclusion.
Limits and common mistakes
Do not infer that an uncrawled URL is deindexed or misidentify a spoofed user agent as a search crawler.
A defensible log workflow begins with access and privacy boundaries. Restrict fields to those needed for crawl analysis, define the time window, and retain an aggregated result rather than sharing raw visitor data. Parse into a reproducible table, then investigate only patterns that can be compared to a known URL inventory. A spike in a parameter URL, for example, is a question about discovery and URL control; it is not yet evidence of a crawl-budget failure.
Preserve the Original Request
Keep the raw request URL and status as immutable evidence. Create derived grouping fields for parameters, paths, bots and response classes. Also identify whether logs come from an edge/CDN or origin: an absent origin request can mean cache handling, not that a crawler did not request the page.