crtlog lets you search certificates recorded in public Certificate Transparency logs. Enter a domain, subdomain or wildcard fragment and we’ll show every certificate that includes it.
Free & API usage limits
- 20 searches per day per IP for browser users.
- 1 search every 5 seconds — slow down if you see a wait message.
- Results are capped at 1,000 certificates per request; use pagination to browse more.
- Scripted access (curl, wget, python-requests) requires an API key — request a 1-month key:
- An API key raises the limit to 500 searches per day.
- Anonymous users see certificate metadata only (no raw DER).
Search by domain, subdomain, or resolved IP address. Learn more.
Off = exact match. On = also matches *.example.com and foo.example.com.
| SANs | Parent domain | Issuer | Not before | Not after | SHA-256 |
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