PEM Certificate Decoder
Inspect X.509 certificate DER metadata including subject, issuer, validity dates, serial number, and signature algorithm.
What this tool does
Inspect X.509 certificate DER metadata including subject, issuer, validity dates, serial number, and signature algorithm.
Where this tool is useful
Decode the public information in a PEM-encoded certificate; do not paste private keys.
Example or format details
Decode the public information in a PEM-encoded certificate; do not paste private keys.
How to use PEM Certificate Decoder
- 1
Paste the technical input into the form and choose any relevant algorithm or formatting options.
- 2
Adjust the fields and options, then select Run tool.
- 3
Inspect the actual result. Copy the text or download the generated file when appropriate.
Privacy and processing
Entered content and chosen files are processed locally in your browser. No conversion request is sent to a freedropper server.
Common questions
What can I use this for?
Decode the public information in a PEM-encoded certificate; do not paste private keys.
What does the tool accept?
Paste the technical input into the form and choose any relevant algorithm or formatting options.
What should I check before using the output?
Only public CERTIFICATE PEM blocks are accepted. The decoded fields do not establish trust, revocation status or that a remote server possesses the matching private key.
Does my input leave my device?
The utility runs in your browser. Selected content is not transmitted to a freedropper conversion service.
How can I reuse the result?
Copy the output or use the download control when the tool produces a file. Check the target application accepts the resulting syntax or file type.