How to read a .CSR file online
Three steps, a few seconds.
Open your .CSR file
Drop it on the box or click to choose it. A bundle holding several certificates is split for you automatically.
Unlock if needed
A password-protected file asks for its export password. It is used only to unlock the file.
Check the details
Read the chain from your certificate up to the root, see every domain it covers, when it expires and copy its SHA-256 fingerprints.
What is a .CSR file?
What's inside .crt, .pem and .p12 files, in plain words.
A CSR file is a Certificate Signing Request, a block of Base64 text generated on your server and submitted to a Certificate Authority to apply for an SSL/TLS certificate. Inspect it with OpenSSL (openssl req -in request.csr -noout -text) or paste it into an online CSR decoder. It is safe to share; it contains only public information.
Programs that open .CSR files
| Full name | Certificate Signing Request (PKCS#10) |
|---|---|
| Developer | RSA Security / IETF (PKCS#10 standard); generated by OpenSSL, web servers and CA tools |
| First released | PKCS#10 published by RSA Security in the 1990s; standardized as RFC 2986 (2000) |
| Category | Data & Other |
| MIME type | application/pkcs10 |
Related viewers
Other free tools to open and preview your files.
Frequently asked questions
Is it safe to open my .CSR file here?
Yes. Certificates are public by design, and decoding and signature checks run with the Web Crypto API.
What does “chain verified” mean?
Each certificate is signed by the one above it. The viewer checks those signatures mathematically, so you can see whether your server certificate, intermediate and root actually belong together - the most common cause of “incomplete chain” errors.
My .p12 / .pfx asks for a password. Which one?
The password chosen when the file was exported (for example from Windows, a browser or your CA's portal). Some files have an empty password - try leaving the field blank.
Why don't you show my private key?
A private key is the secret half of the certificate. Anyone who sees it can impersonate you, so the viewer only tells you that a key is present and what type and size it is.
Can it check if a certificate is revoked?
Not yet. Revocation (OCSP/CRL) needs to contact the certificate authority, which we keep for the server-side version of this tool.
Was this tool helpful?
Your rating helps us decide which tools to improve next.