ciphersmith.io: your offline cipher and crypto toolbox
I used to have a private page with some small hacky tools on creating all kind of things: hashes, base64 encode/decode, generate random noise, creating rsa keys. It was hacky, but it works quite well. Over the few last days, i've let Claude create a neat little user interface (i suck at those things), and we filled in some more features that I felt was missing in a lot of other sites like cyberchef.
All functionality works offline clientside, so nothing gets transferred to a server (check the devtools if you don't believe me), and i probably will open source it soon enough. For now, it's a neat little toolkit that might help you when you are in need of some non-production crypto for testing or development purposes.
Note: there is nothing user-created crypto here. All is using either webcrypto API or a few external npm packages that deal with the crypto. This is merely a neat little frontend.
You can find it at https://ciphersmith.io