Certificate Signing Request Decoder

Decode a PEM-encoded CSR and show subject, SANs, public key, and signature algorithm. Runs entirely in your browser.

Notes

• Uses WebCrypto crypto.subtle.importKey to parse public key + custom DER parser for subject/SANs.
• This is a best-effort decoder — for exact output always use OpenSSL: openssl req -in csr.pem -text -noout.