gchq/cyberchef

CyberChef is a browser-based data transformation tool built by GCHQ, the UK's signals intelligence agency. The problem it solves is the everyday need analysts, security researchers, and developers have to convert, decode, encrypt, or inspect data in various formats without writing custom scripts or installing specialized software. Everything runs inside the browser, so no data ever leaves your machine and there is nothing to install. The interface works through a recipe concept. You drag operations from a searchable list into a central recipe panel, set any options for each operation, and then paste or drop your data into the input box on the right. CyberChef immediately processes your data through every step of the recipe and shows the result in an output box. You can chain any number of operations in sequence, for example, take a string, convert it from Base64 encoding, decompress it with gzip, and then calculate a SHA-256 hash of the result, all in one recipe. Recipes can be saved and shared via a URL that encodes the entire configuration. The operations library is extensive, covering encoding schemes like Base64, Hex, and URL encoding, symmetric encryption algorithms like AES, DES, and Blowfish, hashing algorithms like MD5, SHA-1, and SHA-256, compression formats, network protocol parsing, character set conversions, and many more. There is also an automatic detection mode called Magic that tries to identify and decode nested encoding schemes without you having to guess what they are. You would use CyberChef when analyzing a suspicious file, debugging a data pipeline, reverse engineering an obfuscated payload, verifying encryption, or whenever you need to quickly transform data between formats. It is a JavaScript application that can be used from the hosted site, run locally from a downloaded HTML file, or embedded in other applications via its Node.js API.