About DevDecode

Decode. Convert. Hash. Format.

DevDecode.dev is a collection of 91 free online developer and security tools built for DevOps engineers, security professionals, sysadmins, and developers.

Why DevDecode?

When you're debugging a JWT, decoding a SAML response, or checking a certificate, you need a tool that's fast, reliable, and — critically — doesn't phone home with your sensitive data.

Most tools process input in your browser. Token decoders, certificate parsers, cryptographic utilities, and converters do not upload your input for processing. The DNS Lookup and SSL Checker send the domain you enter to our server; DNS Lookup also queries Google's DNS-over-HTTPS service. Their pages label this distinction before you use them.

How These Tools Are Built

Each tool implements the published specification it is named for — JWTs follow RFC 7519, X.509 certificate parsing follows RFC 5280, TOTP follows RFC 6238, and AES follows NIST FIPS 197.

Cryptographic operations — AES, RSA, SHA hashing, and HMAC — use the browser's native Web Crypto API rather than hand-rolled JavaScript, so results match what OpenSSL and standard libraries produce. Each tool page links the exact standards it implements so you can verify the behaviour yourself.