Certificate CSR Checker
Decode your certificate signing request using our free CSR checker tool
Before submitting your certificate signing request to a Certificate Authority, it’s worth taking a moment to check that everything inside it is correct. A CSR encodes your domain name, organisation details, country, and public key into a single block of text — and if any of that information is wrong, your certificate will either be issued with incorrect details or rejected entirely, causing delays at a frustrating point in the process.
Our free Certificate CSR Checker decodes your CSR request instantly, displaying all the encoded fields in plain English so you can verify your Common Name, organisation details, key algorithm, key size, and Subject Alternative Names (SANs) before anything is submitted. Paste your CSR below or upload the file directly — no OpenSSL knowledge required.
What is a CSR?
Certificate Signing Request
A CSR (Certificate Signing Request) is a block of encoded text that contains information about the organization requesting an SSL certificate and the public key. It is submitted to a Certificate Authority (CA) when applying for an SSL certificate.
What’s Inside a CSR?
A CSR contains information such as your Common Name (domain), Organization, Country, State, Locality, and your public key. This decoder lets you verify all that information before submitting to a CA.
Why Decode a CSR?
Decoding a CSR helps you verify that the information encoded in it is correct before submitting it to a Certificate Authority. This helps prevent delays and errors in the certificate issuance process.
OpenSSL Command Reference
You can also decode and generate CSRs using OpenSSL on the command line:
Decode a CSR
openssl req -in csr.pem -noout -text
Verify a CSR
openssl req -in csr.pem -verify -noout
Generate a CSR
openssl req -new -newkey rsa:2048 -nodes -keyout key.pem -out csr.pem
Generate CSR from Existing Key
openssl req -new -key key.pem -out csr.pem
View CSR Subject Only
openssl req -in csr.pem -noout -subject
Generate CSR with SANs
openssl req -new -newkey rsa:2048 -nodes -keyout key.pem -out csr.pem -addext "subjectAltName=DNS:example.com,DNS:www.example.com"
