Argon2 Hash Generator & Verifier (Argon2id, Argon2i, Argon2d)

Argon2 won the Password Hashing Competition in 2015 and is standardised in RFC 9106. It is deliberately slow and memory-hungry, so each guess costs an attacker real RAM as well as time, which blunts GPU and ASIC cracking. This tool hashes a password with Argon2id, Argon2i or Argon2d — in plain JavaScript inside your browser — and outputs the standard $argon2id$v=19$m=…,t=…,p=…$salt$hash string that libraries such as libsodium, PHP’s password_hash and argon2-cffi read; it also verifies a password against such a string.

How to use this tool

1. Enter the password and pick Argon2id unless you have a reason not to.
2. Set memory (KiB), iterations and parallelism; the defaults are OWASP’s minimum (19 MiB, 2 passes, 1 lane).
3. Leave the salt empty to get a random 16-byte salt, and press Calculate.
4. To check a login, choose verify and paste the stored $argon2… string.

Formula

H₀ = BLAKE2b(p, T, m, t, v, type, P, S, K, X) → fill m KiB of 1 KiB blocks with G(previous, reference), t times → tag = H′(last blocks XORed)

Memory is split into p lanes of 4 segments. Argon2d picks reference blocks from the data (fast, but leaks timing), Argon2i from a counter (side-channel safe), and Argon2id uses the Argon2i method for the first half of the first pass and Argon2d after. G is a BLAKE2b-based compression with multiplications (BlaMka). The PHC string stores the variant, version 19 (0x13), m, t, p, and the salt and hash in Base64 without padding.

Example

With the RFC 9106 test inputs — 32 KiB, 3 passes, 4 lanes, password 32 × 0x01, salt 16 × 0x02, secret 8 × 0x03 and data 12 × 0x04 — Argon2id gives 0d640df58d78766c08c037a34a8b53c9d01ef0452d75b65eb52520e96b01e659, the value in the RFC. Hashing "password" with the salt "somesaltsomesalt", m = 64, t = 2, p = 1 gives $argon2id$v=19$m=64,t=2,p=1$c29tZXNhbHRzb21lc2FsdA$Gpj7qOY5RCXJ….