DER Viewer
View the ASN.1 structure of DER data (Base64 or hex). Paste your data, then click to dissect it. Everything runs on your device, nothing is sent to a server.
Everything runs in your browser. Your data is never sent to our servers.
Example
Example Input
(Base64/hex DER)
Example Output
ASN.1 structure of the DER
How to Use
- 1Paste your data (PEM/Base64/token) into the Input field.
- 2Click the button (or press Ctrl+Enter) to dissect it.
- 3Read the decoded result in the Output field.
About DER Viewer
DER (Distinguished Encoding Rules) is the canonical binary encoding for ASN.1, used in keys, certificates, and CSRs. The DER Viewer shows its contents as a readable tree.
Paste DER data as Base64 or hex; the tool parses and shows its ASN.1 structure (type, length, value). Everything is processed in the browser.
If your data is PEM (with "-----BEGIN…-----" headers), use the PEM Viewer. For format conversion, see PEM ⇄ DER.
FAQ
Are my data or keys sent to a server?
No. DER Viewer runs entirely in your browser using the Web Crypto API and client-side libraries. Your data, passwords, and keys never leave your device.