ASN.1 / DER Decoder
ASN.1 / DER Decoder
Decode DER/BER binary data (hex or Base64/PEM) into a readable ASN.1 tree with tag types, lengths, values, and OID resolution for common cryptographic identifiers.
ASN.1 / DER Decoder
Decode DER/BER binary data (hex or Base64/PEM) into a readable ASN.1 tree with tag types, lengths, values, and OID resolution for common cryptographic identifiers.
Common uses
- Inspect the raw structure of an X.509 certificate
- Decode a DER-encoded public key
- Resolve OIDs in a certificate extension
Frequently asked questions
Can I use ASN.1 / DER Decoder to inspect the raw structure of an X.509 certificate?
Yes. ASN.1 / DER Decoder can inspect the raw structure of an X.509 certificate, directly in your browser.
Can I use ASN.1 / DER Decoder to decode a DER-encoded public key?
Yes. ASN.1 / DER Decoder can decode a DER-encoded public key, directly in your browser.
Can I use ASN.1 / DER Decoder to resolve OIDs in a certificate extension?
Yes. ASN.1 / DER Decoder can resolve OIDs in a certificate extension, directly in your browser.
Is my data uploaded to a server?
No. This tool runs entirely in your browser — your input is processed locally on your device and is never uploaded or stored on a server.