Every SSL certificate starts with a Certificate Signing Request. Before your Certificate Authority can issue a certificate, you need to generate a CSR that contains your domain name, organisation details and public key. The Anonymiz CSR Generator creates both the CSR and matching private key instantly — no OpenSSL installation, no command line.
What Is a CSR?
A Certificate Signing Request is a block of base64-encoded text that you submit to a Certificate Authority when applying for an SSL certificate. It contains your public key and information about your domain and organisation. The CA uses it to generate your certificate — crucially, it does not contain your private key.
The private key is generated alongside the CSR and must be kept secret on your server. The CSR is safe to share — it only contains public information. But if you lose the private key before installing the certificate, the certificate is useless and you need to start over.
How to Generate a CSR
Fill in the following fields in the CSR Generator:
- Common Name — The domain name the certificate will secure. Must match exactly: example.com, www.example.com or *.example.com for wildcard
- Subject Alternative Names — Additional domains to cover. Modern CAs require at least one SAN matching the CN. Add www.example.com if your CN is example.com
- Organisation — Your legal company name. Required for OV and EV certificates, optional for DV
- Country — Two-letter country code (US, GB, DE etc.)
- Key Size — 2048-bit is the standard minimum. 4096-bit for higher security
Click Generate and the tool outputs both the CSR (BEGIN CERTIFICATE REQUEST) and the private key (BEGIN PRIVATE KEY). Save both immediately — the private key is only shown once and is never stored.
What to Do with the CSR
Submit the CSR text to your Certificate Authority. For Lets Encrypt, use Certbot or your hosting panel. For paid CAs like DigiCert or Comodo, paste the CSR during the certificate order process. The CA will validate your domain, sign the CSR with their root certificate and issue your SSL certificate — usually within minutes for DV certificates.
Installing the Certificate
Once issued, install the certificate file and the private key on your server as a matching pair. Use the Certificate Key Matcher to verify they match before restarting the server — a mismatch will prevent the server from starting and take your site offline.
Generate your CSR now with the free CSR Generator — no software needed.
