About this utility
How to use ASN.1 DER Tree Inspector
Parse strict DER tags, lengths, OIDs, strings, nesting, and offsets from PEM, Base64, or hexadecimal data.
What to provide
Paste PEM, Base64, or hexadecimal DER and choose the representation. Indefinite BER lengths are rejected.
- Paste, type, or drag and drop a supported text file into the input area.
- Choose the options that match your intended result.
- Select “Run tool” or press Ctrl/Command + Enter, then copy, download, or move the result back into the first input for another pass.
What the result means
A bounded ASN.1 node table with paths, offsets, tag names, lengths, and safe previews.
Privacy and safety
This utility is loaded as browser code and processes your input only in this tab. OmniCastConverter has no upload endpoint and never stores your content, filenames, tokens, or secrets. Generated markup and code are shown as inert text and are never executed.
Limitations
- Everything is processed in this browser tab. Input, filenames, keys, and output are never uploaded or saved. The tool shows generic DER structure; semantic validation requires the object’s ASN.1 schema and trust policy.
Try the included example
Select “Load example” at any time to restore this tested sample.
30 03 02 01 2A