Snow10 is a simple web app for converting text to zero width unicode characters, which can be hidden in normal messages.
It is inspired by the original program published in ~1998.
Do not use alongside languages/emoji that use zero-width characters. Sorry, it's the way it works.
Threat model: person visually looking at message threads in an app such as Twitter, Matrix, Signal, documents, etc. E.g. abusive family Encrypt the secret message using something like age or keybase before using if encryption is needed. Will not resist forensic analysis. Don't use it over SMS. Privacy: This works client-side and does not log any messages.