Sometimes in my daily work, I need to handle certificates and double-check their details. Questions like, "Is this a new or old certificate? Does it have the SAN I need?" often come up.

Recently, I decided to build my own online certificate decoder – CertDecoder.com. I know there are dozens, if not hundreds, of certificate decoders available online, but I wanted something simple, fast, and reliable for my own use.

Why try Cert Decoder?

If you're juggling certificates at midnight and struggling to keep your eyes open, you need a straightforward tool to quickly verify your certificate details without extra hassle.

Just open CertDecoder.com, paste your PEM-formatted X.509 certificate, and instantly view its details.

  • Privacy-first: All processing happens entirely in your browser, ensuring no certificate data is ever leaked.
  • Retro and minimalist: It's pure HTML—something you rarely see these days, offering a nostalgic, minimalist look.

If you're a web developer, sysadmin, cybersecurity enthusiast, or DevOps junkie, check it out here 👉 CertDecoder.com

I'd greatly appreciate your feedback! 🙏

Feel free to share your suggestions or feature ideas to make it even better.