Question 1

What is a CSR?

Accepted Answer

A CSR (Certificate Signing Request) is a block of encoded text containing your public key and organization information. You submit it to a Certificate Authority (CA) when purchasing an SSL certificate. The CA signs the CSR and returns an SSL certificate.

Question 2

Is the private key secure?

Accepted Answer

Yes. The private key is generated entirely in your browser and never sent to any server. You should save the private key immediately and keep it secret — it is not stored anywhere and cannot be recovered if lost.

Question 3

What key size should I choose?

Accepted Answer

2048-bit is the current industry standard and is accepted by all CAs. 4096-bit provides a higher security margin but is slower for handshakes. Most certificates are issued with 2048-bit keys.

Question 4

What should I enter in Common Name?

Accepted Answer

The Common Name (CN) should be the fully qualified domain name (FQDN) you want to secure — for example, 'example.com' or '*.example.com' for a wildcard certificate. For a multi-domain certificate, enter the primary domain here and add additional domains as Subject Alternative Names.

Question 5

What are Subject Alternative Names (SANs)?

Accepted Answer

SANs allow one certificate to cover multiple domains or subdomains. Modern browsers require the domain to appear in the SAN list (the CN alone is no longer sufficient). Enter one domain per line — the generator will include them in the extensionRequest attribute of the CSR.

Question 6

How do I generate a CSR for SSL?

Accepted Answer

Fill in your organization details (Common Name = your domain, Organization, Country) and click Generate. The tool creates a CSR and private key pair in your browser using the Web Crypto API. Download both files — submit the CSR to your Certificate Authority (CA) and keep the private key secure. Never share the private key.

Question 7

What is a CSR used for?

Accepted Answer

A CSR (Certificate Signing Request) is submitted to a Certificate Authority to obtain an SSL/TLS certificate. It proves you control the domain and provides your public key for inclusion in the certificate. The CA signs the CSR and returns a certificate you install on your web server. Check the CSR with DevDecode's CSR Decoder before submission.

CSR Generator — Free Online Certificate Signing Request Generator

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How to Generate a CSR

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