CSR Decoder
Decode a certificate signing request (CSR): see the subject, requested names, key size and signature, with warnings for weak keys. Private.
Certificate request
Stays in your browserRequest details
Shortcuts: Ctrl+Enter run · Ctrl+Shift+C copy result · / search (use ⌘ on Mac)
Next steps
Done here? Use the Send to… menu on the result to carry it on to Private Key Inspector or Certificate Decoder.
Free Online CSR Decoder
Paste a certificate signing request and see what is inside: who it is for, which host names it asks for, the key and the signature. Problems such as a weak key or a missing name are called out. It gives developers a quick browser-based way to solve a focused csr decoder task before moving the result into a project.
How to decode a CSR
Paste the text that starts with -----BEGIN CERTIFICATE REQUEST----- into the box. The details appear at once. You can also paste just the Base64 part.
What to check
Make sure the Common Name and every host name are in the list of names, the key is at least 2048 bits (RSA) or P-256 (EC), and the request is signed with SHA-256.
Common mistakes
- Leaving the host name out of the SAN list: browsers ignore the Common Name.
- Sending a request made with a 1024-bit key or SHA-1: authorities will reject it.