gchq.github.io/CyberChef (via) CyberChef is “the Cyber Swiss Army Knife—a web app for encryption, encoding, compression and data analysis”—entirely client-side JavaScript with dozens of useful tools for working with different formats and encodings.
It’s maintained and released by GCHQ—the UK government’s signals intelligence security agency.
I didn’t know GCHQ had a presence on GitHub, and I find the URL to this tool absolutely delightful. They first released it back in 2016 and it has over 3,700 commits.
The top maintainers also have suitably anonymous usernames—great work, n1474335, j433866, d98762625 and n1073645.
Recent articles
- Reverse engineering some updates to Claude - 31st July 2025
- Trying out Qwen3 Coder Flash using LM Studio and Open WebUI and LLM - 31st July 2025
- My 2.5 year old laptop can write Space Invaders in JavaScript now, using GLM-4.5 Air and MLX - 29th July 2025