Instantly Decode and Verify Your SSL Certificate with ToolSeel.com
An SSL/TLS certificate is your website's digital passport. It contains crucial information that verifies your site's identity, confirms who issued it, and defines its period of validity. However, the actual certificate file (.crt or .pem) is encoded in the X.509 standard, which appears as an unreadable block of text if you open it. Before you install a certificate or when you need to troubleshoot an SSL issue, how can you be sure all its details are correct?
The Certificate Decoder at ToolSeel.Com is the essential tool for providing this clarity. It allows you to take that encoded text and instantly translate it into a structured, human-readable format. Simply paste the entire content of your certificate file, and our tool will parse it and display all the embedded information. At 5:40 PM on August 26, 2025, web administrators in Colombo and across the world can use this tool to manage their web security with confidence.
Key Certificate Details You Can Verify
Our Certificate Decoder gives you a complete overview of your SSL certificate, allowing you to check the most important details at a glance.
Common Name (Subject): Instantly verify the primary domain name (www.yoursite.lk) that the certificate is issued to.
Issuer Information: See which Certificate Authority (CA), like Let's Encrypt or DigiCert, issued and signed your certificate.
Validity Period: Check the "Valid From" and "Valid To" dates to know exactly when your certificate will expire, which is critical for planning renewals.
Subject Alternative Names (SANs): View the full list of any additional hostnames, subdomains, or IP addresses covered by the certificate.
Cryptographic Details: Inspect the signature algorithm and public key information to ensure it meets modern security standards.
Whether you're installing a new certificate or diagnosing an existing one, the Certificate Decoder at ToolSeel.Com is your go-to utility for fast, free, and accurate verification.
Certificate Decoder Key Features
Instant SSL Decode
Paste your PEM certificate to see its full details in a readable format.
Check Expiry & Domains
Quickly verify the certificate's validity period and all included SANs.
View Certificate Issuer
See who issued the certificate (e.g., Let's Encrypt, GoDaddy, DigiCert).
Troubleshoot SSL Errors
Helps you diagnose common SSL/TLS issues by verifying certificate data.
Safe, Secure & Private
Your certificate is decoded in real-time and never stored on our servers.
Provides OpenSSL Command
Also get the equivalent OpenSSL command to run the same check locally.
Certificate Decoder FAQs
A Certificate Decoder is a tool that parses your SSL/TLS certificate file (in PEM format) and displays its contents in a human-readable format. It lets you easily view all the important details embedded within your certificate, like its issuer and validity period.
Simply copy the entire text from your certificate file, including the '-----BEGIN CERTIFICATE-----' and '-----END CERTIFICATE-----' lines. Paste this block into the input box and click the 'Decode' button. The tool will instantly show you all the certificate's details.
Decoding is essential for verification and troubleshooting. It allows you to confirm that the domain name, issuer, and expiration date are correct before installation. It also helps diagnose common SSL errors by letting you inspect the certificate's details and chain of trust.
The decoder displays crucial information like the Common Name (domain), Subject Alternative Names (SANs), the issuing Certificate Authority (CA), and the certificate's validity period (issue and expiry dates). You can also view details about the signature algorithm and public key.
Yes. While SSL certificates are public information once installed on a server, we do not log or store the data you paste here. The decoding is done in real-time for your session only. Your activity on our tool remains private and confidential.