Log Analysis for AI Crawlers
Server logs reveal exactly how AI crawlers interact with your site. Learn to analyze logs to understand crawler behavior, identify problems, and optimize coverage.
In this guide
- Identifying AI crawlers in logs
- Key metrics to track
- Log analysis commands and tools
- Detecting and fixing crawl issues
Why Analyze Crawler Logs?
Log analysis provides ground truth about AI crawler activity:
Verify Crawling
Confirm which AI crawlers are visiting and how often.
Identify Issues
Find 404s, 500s, slow responses, and blocked requests.
Track Coverage
See which pages crawlers visit and which they miss.
AI Crawler User Agents
Identify AI crawlers by their user agent strings:
| Company | User Agent Pattern |
|---|---|
| OpenAI | GPTBot |
| Anthropic | ClaudeBot, anthropic-ai |
| Google-Extended | |
| Perplexity | PerplexityBot |
| Common Crawl | CCBot |
| Meta | FacebookBot, meta-externalagent |
| Apple | Applebot-Extended |
Basic Log Analysis Commands
# Find all AI crawler requests
grep -E "(GPTBot|ClaudeBot|Google-Extended|PerplexityBot|CCBot)" access.log
# Count requests by AI crawler
grep -E "(GPTBot|ClaudeBot|Google-Extended|PerplexityBot)" access.log | \
grep -oE "(GPTBot|ClaudeBot|Google-Extended|PerplexityBot)" | \
sort | uniq -c | sort -rn
# Find GPTBot requests with status codes
grep "GPTBot" access.log | awk '{print \$9}' | sort | uniq -c
# Find pages GPTBot visited
grep "GPTBot" access.log | awk '{print \$7}' | sort | uniq -c | sort -rn
# Find 4xx/5xx errors for AI crawlers
grep -E "(GPTBot|ClaudeBot)" access.log | awk '\$9 >= 400 {print \$7, \$9}'
# Check response times for AI crawlers
grep "GPTBot" access.log | awk '{print \$NF}' | sort -n | tail -20Key Metrics to Track
Crawl Frequency
How often each AI crawler visits your site:
# Requests per day by crawler
grep "GPTBot" access.log | \
awk '{print \$4}' | cut -d: -f1 | tr -d '[' | \
sort | uniq -cStatus Code Distribution
Track successful vs error responses:
# Status codes for all AI crawlers
grep -E "(GPTBot|ClaudeBot)" access.log | \
awk '{print \$9}' | sort | uniq -c | sort -rnPage Coverage
Which pages are being crawled:
# Top 20 pages crawled by GPTBot
grep "GPTBot" access.log | \
awk '{print \$7}' | sort | uniq -c | sort -rn | head -20Response Time
How fast you're serving AI crawlers:
# Average response time (if logged)
grep "GPTBot" access.log | \
awk '{sum += \$NF; count++} END {print sum/count " ms average"}'Common Issues to Identify
No AI crawler visits
If you see no AI crawler requests, check robots.txt isn't blocking them.
High 4xx error rates
Many 404s indicate broken links or removed content crawlers are trying to access.
5xx errors
Server errors prevent indexing. Investigate and fix immediately.
Only homepage crawled
Check internal linking and sitemap if crawlers aren't discovering deep pages.
Slow response times
Response times over 1s reduce crawl efficiency and coverage.
Log Analysis Tools
GoAccess
Real-time log analyzer with terminal and HTML output. Filter by user agent.
AWStats
Generates reports including robot/crawler statistics.
ELK Stack
Elasticsearch, Logstash, Kibana for advanced log analysis and visualization.
Custom Scripts
Python or shell scripts for specific AI crawler analysis.
Key Takeaway
Logs don't lie.
Server logs provide definitive evidence of AI crawler activity. Regular log analysis helps you verify crawling, identify issues, and ensure your important content is being discovered.
Sources
- GoAccess: Real-time web log analyzer with terminal and HTML output
- Verifying Googlebot: How to verify legitimate bot traffic in logs