Check CSR

Validate your CSR format, inspect key type and strength, and check whether Subject Alternative Names (SANs) are included before submitting to a CA.

100% Free SAN Validation Key Strength Check

Paste your CSR to validate

Format CheckConfirms valid PEM structure

Key StrengthRates key as strong/standard/weak

SAN WarningFlags CSRs missing SANs

All FieldsDisplays subject info decoded

Secure by designYour CSR data is processed instantly over an encrypted connection and never stored on our servers.

Encrypted in transitSubmitted over HTTPS/TLS — nothing is sent in plain text.

Never storedDecoded CSR data is not saved to any database or log.

No third-party sharingYour CSR contents are never shared with ads, trackers, or outside services.

Processed instantlyParsed on request and discarded immediately after the response.

About Check CSR

What Is a CSR Checker?

A CSR checker decodes a Certificate Signing Request and displays its contents in readable form — domain name, organization details, and key details — letting you verify everything is correct before submitting it to a Certificate Authority.

How to Use the CSR Checker

Paste your CSR text
Click Decode
Review the decoded domain and organization details
Confirm everything is correct before submitting to a CA

Key Features

Full CSR decoding — see every field in readable form
Catches errors before submission — avoid CA processing delays from incorrect details
Instant results

Who Uses This Tool

System administrators verify a CSR's details before submitting it. Developers troubleshoot certificate issuance problems by confirming what was actually encoded.

Frequently Asked Questions

What should I check before submitting my CSR?
Confirm the domain name, organization name, and other details exactly match what you intend — mistakes here can delay certificate issuance.

Is this tool free?
Yes, checking a CSR is completely free.

Frequently Asked Questions

Why validate a CSR before submitting?

Validating your CSR catches errors before you pay for a certificate. A malformed CSR will be rejected by your CA and some CAs don't refund. This tool checks format, key size, and SAN inclusion — all common causes of rejection.

What if my CSR has no SANs?

Technically the CA may still issue the certificate, but most modern browsers (Chrome, Firefox, Edge) will show a security warning because they require SANs to validate domain ownership since 2017. Generate a new CSR with SANs using our CSR Generator tool.

What makes a key "weak"?

RSA keys under 2048 bits are considered weak by current standards and may be rejected by major CAs. Keys of 2048 bits meet the minimum standard. 4096-bit RSA or ECC P-256 are considered strong and recommended for new certificates.

Is this tool secure to use?

Yes. A CSR contains only public information — your organization details and public key. It does not contain your private key, so it's safe to paste it into any online validator. Your private key should never be shared or entered into any online tool.