CyberChef

What it is

CyberChef is a web application, published by GCHQ (the UK's signals intelligence and cyber security agency) and open sourced on GitHub, for performing common data transformations without writing code. Its interface is built around dragging small "operations", such as Base64 decode, XOR, various hash functions, regular expression extraction, compression and many more, into a chain called a "recipe", so a multi-step transformation on a piece of data can be built visually and re-run instantly.

Why it is useful

A lot of practical security and forensics work involves data that has been encoded, compressed or lightly obfuscated one or more times, for example a suspicious string found in a log, a piece of malware configuration, or an oddly formatted parameter in a web request. Rather than writing a one-off script for each case, CyberChef lets you stack operations interactively and see the result update live, which is faster for exploratory work and easier to hand to someone else as a saved recipe they can reproduce.

Where it runs

CyberChef runs entirely client-side in the browser using JavaScript; nothing you paste into it is sent to a server, which matters when the data itself might be sensitive, such as a real credential or a private log excerpt. The official hosted version at gchq.github.io/CyberChef works offline once loaded, and the project can also be self-hosted or run as a downloadable standalone version for fully air-gapped environments.

Free versus paid

CyberChef is completely free and open source with no paid tier, hosted directly by GCHQ with no account or sign-up required to use it.

Prerequisites

No programming background is required for basic use, since operations are dragged and configured through the interface. Understanding what you are trying to achieve, for example recognising that a string looks Base64-encoded, comes with general practice in log and data analysis.

Common questions

Is it safe to paste sensitive data into it? Because processing happens entirely in the browser rather than on a server, it is generally considered safe for sensitive data, though using the offline or self-hosted version removes any doubt for especially sensitive material.

Can recipes be saved and shared? Yes, recipes can be exported and shared so a colleague can reproduce the same transformation chain on their own data.

Does it replace scripting entirely? Not for everything; very custom or large-scale transformations still often need a real script, but CyberChef covers a large share of common, ad hoc transformation tasks without one.

Is it maintained? Yes, it remains an actively developed open source project with regular contributions from GCHQ and the wider community.