ASN.1 / DER / PEM Decoder
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PEM type
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Detected / last mode
What is ASN.1 / DER / PEM Decoder?
This tool decodes PEM blocks and DER-encoded ASN.1 data into readable summaries.
It is useful for certificates, CSRs, public keys, private keys, X.509 debugging, and low-level crypto inspection.
How to use ASN.1 / DER / PEM Decoder
- Paste a PEM block, Base64 DER, or hex DER into the input field.
- Choose the matching format or use Auto-detect.
- Click Decode to inspect the ASN.1 summary and any detected certificate, CSR, or key details.
- Copy the normalized PEM, Base64 DER, or hex DER if needed.
Tips
- PEM is just Base64-wrapped DER with BEGIN/END markers.
- This tool is especially useful when debugging certificates and key material.
- If auto-detect fails, explicitly choose PEM, Base64 DER, or hex DER.
- DER is binary, so Base64 and hex are the most convenient text representations.
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ASN.1 / DER / PEM FAQ
Can this tool decode PEM certificates?
Yes. It can parse PEM input and extract readable summary information.
Can it inspect DER input?
Yes. It supports both Base64 DER and hex DER.
Does it support certificates and CSRs?
Yes. It attempts to detect certificates, CSRs, public keys, and private keys.
Is my data stored?
No. The tool only processes the submitted content for decoding.