A crawl diff is useful only when its inputs are comparable. This report surfaces page, issue, response, indexability, title, content, and summary changes between two saved snapshots. By default, after means the latest report and before means the previous report, optionally within one site filter.
Run it
For MCP, use seo_list_reports with category crawl only for discovery. Call seo_describe_report with { "id": "compare-crawl-reports" }, then call seo_run_report with:
{
"id": "compare-crawl-reports",
"params": {
"after": "latest",
"before": "previous",
"site": "sc-domain:example.com"
}
}
Read structuredContent after checking isError. The CLI uses the same parameters:
seo reports describe compare-crawl-reports --json
seo reports run compare-crawl-reports --params '{"after":"latest","before":"previous","site":"sc-domain:example.com"}' --json
Use explicit report ids for a release decision so "latest" cannot move between runs.
Establish comparability first
Read comparability.status before interpreting any delta. The accompanying flags show whether the definition ids, config hashes, sites, start URLs, modes, request scopes, and caps match. before and after preserve each report id, status, normalized config, explicit requestScope, caps, request-evidence status, joined data-source status, warnings, caveats, and completeness. This is enough to assess the inputs without loading two separate reports.
Next inspect top-level completeness. If truncated is true, or either input is partial or failed, read its stable reason codes and the report-level caveats. An absent page from a capped, skipped, failed, or differently scoped crawl is not proven removed. Source row caps also limit joined GSC or GA4 evidence even when the document crawl completed.
Only then inspect summary, pageChanges, and issueChanges. These fields describe retained observations between the named snapshots. Health and GEO score deltas are derived summaries, not ranking or AI-visibility evidence. Prioritize newly observed response failures and unintended indexability flips, then verify titles, content, and issue groups on the affected URLs. Confirm fixes with the same definition and request scope after deployment. When comparability requires review, describe the change as observed between snapshots and name the differing scope, cap, configuration, or incomplete source instead of attributing it to the release.