What this means
A fetch error occurs when SEODiff's crawler could not retrieve a page at all. This is the most severe issue because if your pages can't be loaded, they can't be indexed by any search engine or AI system. The JSON field is fetch_errors.
Detection condition
Triggered when a page's Error field is non-empty. Common error types include DNS resolution failures, connection timeouts, TLS errors, and malformed HTML that crashes the parser.
Impact on scores
Severity weight: 20 (highest). Deductions: −30 on Indexability, −25 on Hygiene. A site with even 5% fetch errors will see significant score drops.
Common causes
- Server errors: Application crashes, database timeouts, or misconfigured reverse proxies.
- Rate limiting: Server throttling the crawler (429 responses or connection resets).
- DNS issues: Subdomains or CDN endpoints not resolving.
- SSL certificate problems: Expired or misconfigured certificates.
- Firewall/WAF blocks: Security rules blocking the crawler's user agent or IP.
How to fix
- Check your server logs for the affected URLs during the scan timeframe.
- Verify the pages load correctly in a browser and with
curl.
- If rate limiting: increase your server's request capacity or configure SEODiff's crawl rate.
- If WAF blocking: whitelist SEODiff's user agent or IP range.
- Re-scan to confirm the errors are resolved.