An access log records requests handled by a server. It can show that a URL was requested and what the server returned. It cannot, by itself, tell you whether a page was indexed, whether a visitor understood it, or why a crawler chose that URL. For those questions, combine logs with page checks and Search Console.
Read the fields before counting requests
Log formats vary. In Apache’s combined log format, a row can contain the client address, time, request method and path, status code, bytes sent, referrer, and user agent. A host or CDN may add or omit fields. Ask for the format definition along with the export so a column is not mistaken for another measure.
| Field | Question it helps answer |
|---|---|
| Time and time zone | When did an error start, and does it match a deployment or outage? |
| Method and path | Which page or file was requested? Separate page URLs from images, scripts, and API calls. |
| Status | Did the server return success, a redirect, a missing page, or a server error? |
| User agent and source address | What did the requester claim to be, and can a crawler identity be verified? |
| Referrer and response size | Where might a request have come from, and was a response unexpectedly small? |
Do not assume every 404 is a crisis. Some requests are for obsolete or invented paths. Prioritize a missing URL that people or a verified crawler repeatedly request, especially when it should lead to a current page. A 5xx response on an important page deserves prompt investigation because the server failed to serve it at that time.
A simple first analysis
- Define a period. Export a few representative days and note the time zone. If you are investigating a release, include time before and after it.
- Normalize the data. Confirm that each row has the same field order, and keep the original file untouched. Put a working copy in a tool that can filter and group rows.
- Filter to relevant requests. For a page-crawl question, separate HTML paths from assets and exclude internal monitoring where you can identify it reliably.
- Group by path and status. Look for repeated 404s, 5xx responses, or redirect chains on pages that matter.
- Open the affected URL. Test what it returns now and whether internal links or sitemaps still point to it. Record the fix and check a later log export.
For example, suppose a log shows repeated requests for /old-guide/ returning 404. That is a hypothetical finding, not a result from this site. Check whether the old URL had a real replacement. If it did, a redirect and corrected internal links may be appropriate. If the path was never a page, a redirect could send readers to something irrelevant.
Use logs for SEO questions with care
Google’s crawling guide notes that Search Console’s Crawl Stats report gives a site-level history, while logs can help determine whether a specific URL was requested. A request is evidence of crawling, not indexing. If the page is absent from search, inspect its indexing state separately.
A user-agent string that says “Googlebot” is not proof that Google made the request; other clients can copy it. Google’s verification guide describes checking the source IP against published ranges or doing reverse and forward DNS checks. Use verified requests when making decisions about crawler behavior.
If a CDN serves cached pages, the origin log may omit requests answered at the edge. Decide whether you need origin logs, CDN logs, or both before drawing conclusions about traffic. Keep raw logs private: they can contain addresses, URLs, and other request details that should not be pasted into a public report.
What a file analyser should help you do
Choose a tool that can import your actual log format, preserve the original rows, filter by date and path, group status codes, and export the rows behind a chart. For a small file, a spreadsheet may be enough. For a large or mixed-format export, use a parser that handles quoted fields and time zones correctly. Check a handful of rows manually before trusting a summary.
The final output should be a short list of affected URLs, the evidence for each, the fix, and a date to recheck it. That is more useful than a dashboard of request counts without a decision.
Frequently asked questions
What is log file analysis?
It is examining recorded requests to understand what a server received and returned. For a website, it can reveal repeated errors, redirects, and requests for particular pages. It does not establish whether those pages were indexed or useful to readers.
How do you analyze website logs?
Get the log format and a dated export, confirm the fields and time zone, then filter by the question you are investigating. Group relevant rows by path, status, and date. Test the affected URLs, make a specific fix, and compare a later export.
What can SEO log analysis show?
It can show whether a verified crawler requested a specific URL and what response the server logged. It can also reveal errors and redirect requests. Use Search Console or other page checks to investigate indexing; crawling and indexing are different events.
How do you choose a log file analyzer?
Check that it imports your server or CDN log format, handles quoted fields and time zones, lets you filter by URL and status, and allows you to inspect original rows behind summaries. A spreadsheet may suffice for a small, consistent export.
What does a web server log entry contain?
It depends on the configuration. A typical access log may include a client address, timestamp, request method and path, response status, bytes sent, referrer, and user agent. Read the format definition supplied by the host before treating a column as a specific measure.
Lorelei has been an online entrepreneur, marketer and writer since 2006. Her biggest passion is WordPress, which is why she switched to being a full-time blogger 20 years ago and hasn’t looked back since. With so many years of experience behind her, she is an expert in copywriting, SEO, marketing and business strategies.
