PEM Certificate Viewer
Parse a PEM-encoded X.509 certificate and view its subject, issuer, validity, serial number and extensions.
What is PEM Certificate Viewer?
Inspect the contents of a PEM-encoded X.509 certificate directly in your browser. Paste a certificate to view its subject, issuer, validity period, serial number, public key information and available certificate extensions.
How to use
- Paste a PEM-encoded X.509 certificate.
- Parse the certificate.
- Review the certificate subject and issuer.
- Check the validity period and serial number.
- Inspect the public key and certificate extensions.
Features
- PEM certificate parsing
- X.509 certificate details
- Subject and issuer information
- Validity period
- Serial number
- Public key information
- Certificate extensions
- Local browser processing
Common Use Cases
- Inspecting TLS certificates
- Debugging HTTPS configuration
- Checking certificate metadata
- Certificate development and testing
- Investigating certificate extensions
Example
-----BEGIN CERTIFICATE----- MIIB...certificate data... -----END CERTIFICATE-----
Certificate type: X.509 Subject: CN=example.com Issuer: CN=Example CA Valid from: 2026-01-01 Valid until: 2027-01-01 Serial number: 01A4B72C
FAQ
What certificates can the tool inspect?
The viewer is designed to parse PEM-encoded X.509 certificates such as certificates commonly used for TLS and HTTPS.
What certificate information is displayed?
The viewer can display information such as the subject, issuer, serial number, validity period, public key details and supported extensions.
Can I inspect a TLS certificate?
Yes. You can paste the PEM representation of an X.509 TLS certificate and inspect its encoded certificate information.
Does the tool verify whether a certificate is trusted?
No. Parsing a certificate and displaying its contents does not establish whether the certificate is trusted by a particular operating system, browser or certificate authority store.
Does the tool check certificate expiration?
It displays the certificate validity period so you can see its start and expiration dates. Dedicated expiration checking can provide a more focused validity check.
Is the certificate uploaded to a server?
No. Certificate parsing is performed in the browser, so the PEM data does not need to be uploaded to the server.
Missing a feature?
If this tool doesn't cover your use case or is missing functionality, please let me know through the Contact page.
New improvements and features are added based on user feedback.