Argon2 hash

That's by design. Hash mode generates a fresh random 16-byte salt on every run, and the salt is part of the PHC output — so two hashes of the same password never match. To check a password against an existing hash, use verify mode instead of comparing strings.

Switch the mode to verify, enter the password, and paste the full PHC string (everything from $argon2id$… onward) into the hash field. The memory, iteration, and parallelism parameters are read from the string itself, so you don't need to know what settings produced it. Hashes made with the argon2i or argon2d variants verify too — the algorithm is taken from the PHC string.

Memory cost from 8 KiB up to 1,048,576 KiB (1 GiB), iterations 1–50, and parallelism 1–16. The defaults — 19,456 KiB (19 MiB), 2 iterations, 1 lane — follow the current OWASP recommendation for Argon2id. Raising memory is generally the most effective way to make cracking more expensive.

The hash and verify computations run entirely in your browser via WebAssembly; the password is never sent to a server. That said, for production systems you should hash passwords server-side at the point of storage — this tool is for testing, debugging, and generating hashes you control.