X.509 Certificate Decoder
Parse and dissect public key infrastructure (PKI) X.509 certificates to examine extensions, subject metadata, algorithm signatures, and key specs.
Ready to decode X.509 certificate...
Ready
X.509 Specification Reference
1. ASN.1 Structure
X.509 certificates are formatted using Abstract Syntax Notation One (ASN.1) rules serialized typically via Distinguished Encoding Rules (DER).
2. Version 3 Extensions
X.509 v3 introduced extensible fields allowing customized data inclusions like Basic Constraints, Key Usage policies, and SAN definitions.
How to use X.509 Certificate Decoder
- Enter or paste the values requested in the input fields.
- Choose any options provided, then run an action button if the tool requires one.
- Review the result and copy or adjust it as needed.
X.509 Certificate Decoder features
- Available tool controls: Decode X.509 Object.
- Input and option fields: Paste X.509 Certificate PEM Data (-----BEGIN CERTIFICATE-----):, X.509 Quick Summary:, Full ASN.1 Attribute Breakdown:.
Frequently Asked Questions (FAQ)
No. All X.509 decoding routines run locally client-side inside your browser engine without network transit.
Object Identifiers (OIDs) like `2.5.4.3` map directly to standard attributes such as Common Name (CN) within distinguished names.
Yes, self-signed certificates follow the exact same X.509 v3 syntax framework and parse correctly using standard PEM boundaries.