Free Online Certificate Decoder

Certificate Decoder

Paste Certificate Text

Image Verification *

About Certificate Decoder

The Certificate Decoder tool allows you to decode and view detailed information from SSL/TLS certificates quickly and easily. When you receive or download a certificate file, the data is encoded in Base64 format, making it difficult to read manually. This tool converts that encoded data into a human-readable format for better understanding and verification.

Whether you are a web developer, IT professional, or site owner, the Certificate Decoder helps ensure your SSL certificates are properly installed and valid.

What Is a Certificate Decoder Tool?

A Certificate Decoder is an online tool that decodes SSL certificate files such as .crt, .pem, or .cer into readable details. It extracts key information like the issuer name, validity period, subject (domain details), and public key.

For example, when you paste a certificate that looks like this:

-----BEGIN CERTIFICATE-----
MIIDdzCCAl+gAwIBAgIEUzS5hzANBgkqhkiG9w0BAQsFADBvMQswCQYDVQQGEwJJ
...
-----END CERTIFICATE-----

The SSL Certificate Decoder will decode it to show you important details like who issued it, for which domain, and until when it’s valid.

Why Use an Online Certificate Decoder?

Here’s why using a Certificate Decoder is essential:

• Instant Results: Decode certificates in seconds.
• Verify Certificate Details: Check domain, issuer, and validity information.
• Troubleshoot SSL Issues: Detect expired or mismatched certificates.
• No Installation Needed: Works completely online.
• Free and Secure: 100% safe and privacy-friendly.

This SSL certificate decoder helps you validate certificates before deployment or renewal.

How to Use the Certificate Decoder Tool

Using the decode certificate online tool is simple and straightforward:

1. Copy the contents of your SSL certificate file (.crt, .pem, or .cer).
2. Paste it into the tool’s input box.
3. Click “Decode Certificate.”
4. Instantly view decoded details including domain name, organization, validity dates, and issuer information.

It’s fast, reliable, and requires no technical expertise.

Features of the Certificate Decoder Tool

• Instant SSL Decoding: Quickly decode any SSL/TLS certificate.
• Detailed Certificate Info: View subject, issuer, serial number, signature, and validity.
• Supports All Formats: Works with PEM, DER, CRT, and CER files.
• Cross-Platform Access: Works on all devices and browsers.
• Completely Free: No sign-up or software installation required.
• Secure Processing: Data stays private and is not stored or shared.

The SSL decoder tool helps professionals check certificates used in web servers, APIs, and email systems.

Benefits of Using an SSL Certificate Decoder

• Check Domain Ownership: Verify if the certificate matches your domain.
• Confirm Validity Period: Ensure your SSL certificate is active and not expired.
• Avoid Configuration Errors: Identify invalid or misissued certificates.
• Improve Security: Detect any untrusted or self-signed certificates.
• Save Time: Decode multiple certificates instantly without using OpenSSL.

This certificate viewer is a quick solution for managing SSL and improving website security.

What Information Does a Certificate Decoder Show?

When you decode an SSL certificate, you can view the following details:

• Common Name (CN): The domain name protected by the certificate.
• Organization (O): The entity or company that owns the certificate.
• Organizational Unit (OU): Department or business unit (optional).
• Issuer: The Certificate Authority that issued the SSL certificate.
• Serial Number: A unique identifier for the certificate.
• Validity Period: Start and expiry dates.
• Signature Algorithm: The encryption method used for signing.
• Public Key: The key used for establishing secure connections.

All of these details are extracted from your encoded SSL certificate for easy verification.

Frequently Asked Questions (FAQs)

Q1. What is a Certificate Decoder?
A Certificate Decoder is a tool that decodes encoded SSL/TLS certificates to show readable details about their configuration and ownership.

Q2. Is this tool free to use?
Yes, the Certificate Decoder is completely free and requires no registration.

Q3. Which file formats are supported?
It supports .pem, .crt, .cer, and .der certificate files.

Q4. Can it decode expired certificates?
Yes, you can decode both valid and expired certificates to view details.

Q5. Is my certificate data safe?
Yes, your data is processed securely in your browser and not uploaded to any server.

Q6. Can I check who issued my SSL certificate?
Yes, the decoder shows the Certificate Authority (CA) that issued it.

Q7. Does it show wildcard or SAN certificate details?
Yes, the decoder can display Subject Alternative Names (SANs) as well.

Conclusion

The Certificate Decoder is a fast, secure, and user-friendly tool that allows you to decode SSL certificates and view important details instantly. It helps you confirm ownership, check validity, and verify the authenticity of your certificates.

Whether you’re managing multiple domains or setting up SSL for a single website, this SSL certificate decoder ensures full transparency and security. Try it now and decode your SSL certificate online for free.