CyberChef is the "cyber swiss army knife", a workbench built by GCHQ for the kind of data wrangling that usually costs you an afternoon and six sketchy online converters. Pick from several hundred operations, stack them into a recipe, and watch your input transform one step at a time.

The trick is the stacking. A single Base64 decode is unremarkable. Base64 decode, then gunzip, then parse as a JWT, then pretty-print the JSON, all chained and re-running live as you tweak the input, is the part that turns a fiddly job into a few clicks.

Everything runs in your browser. Your instance serves the page and then gets out of the way, so whatever you paste in never reaches a server, ours included.

What you get

• Several hundred operations, covering Base64, hex and URL encoding, hashing from MD5 through SHA-3, AES, RSA and PGP, gzip and zip, JSON, XML and CSV parsing, regex extraction, diffing, character encodings, and a pile of classical ciphers.
• Recipes. Chain operations, drag to reorder, disable a step to see what it was doing, and step through them one at a time when something misbehaves.
• Deep links. Save a recipe as a URL and whoever clicks it lands on the same setup.
• Magic. Point it at unidentified data and it guesses the encoding and what to do about it.
• Drag and drop files, including images and binaries, with a hex editor and entropy visualiser built in.
• Your own instance, behind your ElfHosted login. No queue, no rate limit, and no third party watching what you decode.

Part of the Flex collection, so you can run it alongside other Flex apps and swap what is running whenever you like.