Certificate Workbench

Certificate Inspector

Domains, expiry & key details

Inspect certificate domains, issuer, validity and key information locally.

🔒 Local-only · No upload · No storage

Try an example

TEST ONLY · Public synthetic examples. Never use these keys for real services.

Advanced information / extensions

Inputs and results are cleared when edited, cleared or when leaving this page. Copy and file saving happen only when you request them.

PEM text only · up to 1 MiB, 20 blocks, 128 KiB per block. DER, PFX/PKCS#12, JKS and encrypted keys are not supported in v1.

Usage guideWhen to use · How to use · Understand results

When to use this tool

Inspect a PEM certificate before installation or renewal to check domains, SANs, issuer and validity dates.

Paste certificate PEM or read a local PEM file. The synthetic example is a safe way to explore the result layout.
Inspect the domain list, validity, public key and extensions against your intended deployment.

Date validity is only one check. The page does not contact the TLS server or establish public trust, hostname suitability or revocation status.