CyberChef is a simple, intuitive web app for carrying out all manner of
"cyber" operations within a web browser. These operations include
creating hexdumps, simple encoding like XOR or Base64, more complex
encryption like AES, DES and Blowfish, data compression and
decompression, calculating hashes and checksums, IPv6 and X.509
parsing, and much more.

WWWW: https://github.com/gchq/CyberChef/wiki