CyberChef README

The project's README from github.com/gchq/CyberChef. As one markdown file: README.md.

CyberChef

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The Cyber Swiss Army Knife

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

The tool is designed to enable both technical and non-technical analysts to manipulate data in complex ways without having to deal with complex tools or algorithms. It was conceived, designed, built and incrementally improved by an analyst in their 10% innovation time over several years.

Contents

Official website

CyberChef's official website can be found here - have fun!

Running Locally

You can run CyberChef with Docker (no toolchain required) or build it from source with Node.js.

With Docker

Prerequisites

Option 1: Build the Docker Image Yourself

  1. Build the docker image
docker build --tag cyberchef --ulimit nofile=10000 .
  1. Run the docker container
docker run -it -p 8080:8080 cyberchef
  1. Navigate to http://localhost:8080 in your browser

Option 2: Use the pre-built Docker Image

If you prefer to skip the build process, you can use the pre-built image

docker run -it -p 8080:8080 ghcr.io/gchq/cyberchef:latest

Just like before, navigate to http://localhost:8080 in your browser.

This image is built and published through our GitHub Workflows.

From source

If you want to develop CyberChef or run it without Docker, you can build it directly with Node.js.

Prerequisites

[!NOTE]

You can use nvm to manage Node.js versions and use the current development version in this project to avoid conflicts with other projects on your machine.

Setup

git clone https://github.com/gchq/CyberChef.git
cd CyberChef
npm install

Common tasks

Command Description
npm start Run the development server with live reload at http://localhost:8080.
npm run build Produce a production build in the build/prod directory.
npm test Run the Node.js and operation test suites.
npm run testui Run the browser (UI) tests.
npm run lint Check the code against the linting rules.
npm run newop Scaffold a new operation via the interactive quickstart script.

If you hit an out-of-memory error while building large recipes, increase Node's heap size with npm run setheapsize.

How it works

There are four main areas in CyberChef:

  1. The input box in the top right, where you can paste, type or drag the text or file you want to operate on.
  2. The output box in the bottom right, where the outcome of your processing will be displayed.
  3. The operations list on the far left, where you can find all the operations that CyberChef is capable of in categorised lists, or by searching.
  4. The recipe area in the middle, where you can drag the operations that you want to use and specify arguments and options.

You can use as many operations as you like in simple or complex ways. Some examples are as follows:

Features

Deep linking

By manipulating CyberChef's URL hash, you can change the initial settings with which the page opens. The format is https://gchq.github.io/CyberChef/#recipe=Operation()&input=...

Supported arguments are recipe, input (encoded in Base64), and theme.

Browser support

CyberChef is built to support

Node.js support

CyberChef is built to fully support Node.js v24 and is also tested against Node.js v26 ahead of it becoming the active LTS release. For more information, see the "Node API" wiki page

Security

Please see the CyberChef security policy.

Contributing

Contributing a new operation to CyberChef is super easy! The quickstart script will walk you through the process. If you can write basic JavaScript, you can write a CyberChef operation.

An installation walkthrough, how-to guides for adding new operations and themes, descriptions of the repository structure, available data types and coding conventions can all be found in the "Contributing" wiki page.

Licencing

CyberChef is released under the Apache 2.0 Licence and is covered by Crown Copyright.

CyberChef (gchq/CyberChef)

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36.1K ·GitHub
CyberChef
What is this?CyberChef is a web app that bundles encoding, encryption, compression, hashing and other data-analysis operations ('cyber' operations) into a single drag-and-drop recipe builder that runs entirely in your browser.
Is this a hosted website or something I have to install?It's primarily a hosted web app (there's an official site you can use directly), but since all processing happens client-side, you can also download it and run it locally via Docker or by building it with Node.js.
How do I get it running on my own machine?Either build and run the Docker image (or use the pre-built one) and open it in your browser, or clone the repo and run `npm start` for a dev server with live reload, `npm run build` for a production build.
Are there any size or browser limits I should know about?Files up to roughly 2GB can be loaded, though very large inputs may make some operations slow, and the app officially targets Chrome 50+ and Firefox 38+.
Does any of my input data get sent to CyberChef's server?No. All baking (recipe execution) happens locally in your browser; your recipe, input text and files never leave your machine.
Can I save or share a recipe I build?Yes, you can save a recipe to local storage to reuse later, or copy the URL (which encodes the recipe and input) to share the exact setup with someone else.
What is the 'magic' auto-detect feature?CyberChef tries several techniques to guess how your data is encoded; if it finds a matching operation, it shows a magic-wand icon in the output that you can click to decode the data automatically.
Why did GCHQ build this instead of using existing crypto/encoding tools?It started as one GCHQ analyst's personal project during their 10% innovation time, built so both technical and non-technical analysts could manipulate data (encoding, encryption, compression, hashing) without wrestling with separate complex tools.
Can I step through a recipe to debug it?Yes, you can set breakpoints on any operation and step through the recipe one operation at a time to inspect the data at each stage.
What are similar projects?awesome-ctf, x64dbg, javascript-obfuscator, flowsint, MyIP, awesome-hacking, hacker-roadmap, Claude-Red
Which topics is it in?hashing, encoding, forensics, ctf, parsing, compression, data-analysis, reverse-engineering, cybersecurity, encryption, browser, web-app
Creator
gchq
Size
147.1 MB
Stars
36.1K
Updated
CommitOct 16Releasev11.5.0Sep 18
Age
9y
Commits · 90 Days