CSR Decoder
Decode a PEM-encoded Certificate Signing Request and inspect its subject, public key and requested certificate extensions.
What is CSR Decoder?
Decode a PEM-encoded Certificate Signing Request and inspect the information contained inside it. View the certificate subject, public key details, signature algorithm and requested extensions without needing command-line certificate tools.
How to use
- Paste a PEM-encoded certificate signing request.
- Decode and validate the CSR structure.
- Review the certificate subject.
- Inspect the public key and signature information.
- Review requested certificate extensions when present.
Features
- PEM CSR decoding
- CSR structure inspection
- Subject information
- Public key information
- Signature algorithm
- Requested extensions
- CSR validation
- Browser-side processing
Common Use Cases
- Inspecting generated CSRs
- Debugging certificate requests
- Checking certificate subject fields
- Reviewing requested domains
- Certificate development and testing
Example
-----BEGIN CERTIFICATE REQUEST----- MIIC...CSR data... -----END CERTIFICATE REQUEST-----
Type: PKCS#10 Certificate Signing Request Subject: CN=example.com Public Key: RSA 2048-bit Signature Algorithm: SHA-256 with RSA Requested SANs: example.com, www.example.com
FAQ
What is a CSR decoder used for?
It allows you to inspect the information contained in a Certificate Signing Request, including its subject, public key and requested extensions.
Can it decode PEM-encoded CSRs?
Yes. The tool is designed to parse PEM-encoded PKCS#10 Certificate Signing Requests.
Can I see the domains requested in a CSR?
Yes, when the CSR contains a Subject Alternative Name extension, the requested names can be displayed.
Can the tool recover the private key from a CSR?
No. A CSR contains the public key and certificate request information, not the corresponding private key.
Does decoding a CSR verify the resulting certificate?
No. A CSR can be inspected and its signature checked independently, but decoding it does not mean that a certificate authority has issued or trusted a certificate.
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.