Try it out
Are there any fundamental issues with the concept of a web based password manager?
Should I be concerned if hashes linger in memory longer than they should or is there some fundamental issue with how browsers work that makes this system insecure?
Here is the main source file, if you want to take a closer look.
EDIT: To clarify, this app runs 100% locally, has no external dependencies and doesn't store any information except some settings in a cookie if you want to.
This is a deterministic, hashing password manager.
EDIT 2, to be extra specific: If I store user input in a variable, and the resulting hash in another variable, how plausible is the threat of that information leaking?