Compare two saved diagnostic reports side by side, field by field.
Report Diff lines up two saved diagnostic reports and highlights exactly what changed between them. Paste the report ID (or the full share URL — the ID is parsed out) for each side, and the tool loads both public snapshots and builds a structured, field-level comparison: domain, per-check status, score, and other key metrics, each marked as the same or changed.
It is handy for before/after checks — re-run a diagnosis after a DNS change, a certificate renewal, or a CDN switch, then diff the new report against the old one to confirm the fix landed. Reports of different kinds (for example a combo diagnosis vs. a single probe) are not comparable field by field, and the tool tells you so instead of showing a misleading diff.
Every saved report has a share URL like /r/<id>. Paste either the full URL or just the id part into each field; the tool extracts the id for you.
Field-level diff only makes sense between reports of the same kind. Comparing a full diagnosis report with a single-probe snapshot, for example, has no shared structure, so the tool reports them as not comparable.
No new data is created. The tool only reads the two public report snapshots you reference by id and compares them in your browser.