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YFT
Client-side ProcessingUpdated 2026-02-11Report issue

Runs fully in your browser. Inputs stay on your device. See recent fixes on changelog.

SSL Certificate Decoder

Decode PEM-encoded SSL/TLS certificates and inspect fields.

FreeRuns in browsercertificate decoderssl certificate parser

Parses X.509 certificates and shows subject, issuer, dates, and extensions.

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Cmd/Ctrl+Enter Primary actionCmd/Ctrl+Shift+L Load sampleCmd/Ctrl+Shift+X Clear/resetCmd/Ctrl+Shift+C Copy result

About SSL Certificate Decoder

Decode PEM-encoded SSL/TLS certificates and inspect fields. Decode and inspect SSL/TLS certificates online for free. View subject, issuer, validity dates, and X.509 extensions from PEM-encoded certificate data. Implements standard encoding and decoding algorithms that produce output compatible with all major programming languages and platforms. Supports both encoding and decoding in a single interface. Everything runs client-side in your browser for maximum speed and privacy — no data is sent to any server, and no signup is required.

Related tools: Certificate Chain Checker, RSA Key Pair Generator, JWT Token Generator

How to Use SSL Certificate Decoder

  1. Enter text or data in the input field.
  2. Click Encode or Decode depending on your goal.
  3. Copy the output to your clipboard.

Frequently Asked Questions

What is SSL Certificate Decoder?
Decode and inspect SSL/TLS certificates online for free. View subject, issuer, validity dates, and X.509 extensions from PEM-encoded certificate data.
What encoding standards are used?
This tool follows the official encoding specifications, including RFC standards where applicable. The implementation matches widely-used libraries so the output is compatible with other systems and programming languages.
Can I encode binary data?
The tool primarily handles text input, but many encoding formats such as Base64 are designed to represent binary data as text. You can paste Base64-encoded binary data for decoding or encode text into a binary-safe format.
Is the encoding reversible?
Yes, all encoding operations provided by this tool are fully reversible. You can encode text and then decode it back to get the exact original content without any data loss.
Is SSL Certificate Decoder free to use?
Yes, encoding and decoding are completely free with no usage limits. The tool runs in your browser and requires no registration.
Is my data safe when using SSL Certificate Decoder?
Yes, all encoding and decoding happens locally in your browser. No data leaves your device, so your input remains completely private.

Related Tools

Certificate Chain Checker
Validate SSL/TLS certificate chains and check expiration dates.
RSA Key Pair Generator
Generate RSA public and private key pairs in PEM format.
JWT Token Generator
Create signed JWT tokens with custom claims and algorithms.