Open CSR Files Online
A CSR is what you send to a certificate authority to get a certificate. It contains your public key, the subject and requested domain names.
Certificate Signing Request · .csr
What you see in the CSR viewer
- Subject and requested domains
- Public key algorithm and size
- A check that the request's signature is valid
- The PEM text to copy
Other ways to open CSR files
Windows
certutil or OpenSSL on the command line.
macOS
OpenSSL in Terminal.
Phone & tablet
This viewer is the practical option.
Frequently asked questions
Is my CSR file uploaded?
No. The file is read by your browser and shown on your own device. Nothing is sent to a server, and it is gone when you close the tab.
How do I open a CSR file without installing software?
Drop the .csr file on this page. It opens straight away in the SSL Certificate Viewer, on Windows, macOS, Linux, Android and iPhone alike.
What if my CSR file doesn't open?
The viewer checks the file's content, not just its name. If it is damaged or not really a CSR file, you'll see an error or can switch to the hex view to look at the raw bytes.