Executive summary
Server logs are the ground truth for crawler behaviour. Collect a representative window, verify which requests are genuine bots, then analyse where crawl effort lands, which valuable pages are ignored, and how quickly new content is discovered. Logs turn crawl-budget debates into evidence-led decisions.
What this helps you decide
Which crawl-efficiency and indexation changes are justified by how crawlers actually behave on your site.
Business problem
Crawl tools show what a site could offer crawlers; only server logs show what crawlers actually do. Without them, teams guess about crawl budget, missed pages and bot behaviour, and often guess wrong.
Step-by-step process
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1
Collect a representative window
Gather at least two to four weeks of raw access logs so patterns and infrequently crawled sections are visible.
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2
Verify genuine crawlers
Confirm bot requests by reverse-DNS or published IP ranges, because many requests spoof search-engine user-agents.
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3
Segment by bot and section
Break hits down by crawler and by URL pattern to see where each spends its effort across the site.
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4
Find the waste and the gaps
Identify low-value patterns absorbing crawls and, crucially, valuable pages that receive few or no crawler hits.
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5
Measure discovery and errors
Check how long new pages take to be crawled and how many crawler requests hit 404s, 5xx errors or redirects.
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6
Turn findings into actions
Feed the results into crawl-budget, redirect and architecture fixes, prioritising the valuable pages crawlers currently miss.
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7
Set a recurring pull
Automate a regular log export so crawl behaviour becomes a monitored metric rather than a one-off study.
Worked example
Checklist
- Collect at least two to four weeks of raw access logs
- Verify bots by reverse-DNS or official IP ranges
- Segment crawl hits by bot and URL pattern
- Flag both wasted crawls and under-crawled valuable pages
- Measure discovery time and crawler error rates
- Automate a recurring log pull for ongoing monitoring
Common mistakes
- Trusting the user-agent string without verifying the request is a genuine crawler
- Analysing a window too short to reveal how rarely deep sections are crawled
- Studying logs once and never turning the findings into crawl or architecture fixes
30-minute experiment
KPIs to track
- Share of verified crawler hits on valuable pages
- Average discovery time for new pages
- Crawler error-response rate
FAQs
How much log data do I need?
Two to four weeks is a sensible minimum. It is long enough to reveal patterns and to include sections that crawlers visit only occasionally.
Why verify crawlers instead of trusting the user-agent?
Because scrapers and bots routinely spoof search-engine user-agents. Reverse-DNS or official IP verification ensures your analysis reflects real crawler behaviour.
Recommended next steps
Where this fits - and what's next
The SearchScore path from a problem you feel to visibility you can measure.