How to identify and crack an Argon2 hash

Argon2 is an key-derivation hash type. It uses a deliberately slow, salted key-derivation scheme, so only weak or short passwords are realistically recoverable. This page shows how to recognise it and the exact commands to attack it.

All identification runs locally in WebAssembly. The commands below write the hash to a local file on your machine — nothing is sent to this site.

Identifying the hash

The hash identifier on the home page detects Argon2 entirely in your browser — your hash is never uploaded. A typical example looks like this:

$argon2id$v=19$m=65536,t=3,p=4$c29tZXNhbHQ$RdescudvJCsgt3ub+b+dWRWJTmaaJObG

Cracking Argon2 with hashcat

Save the hash to a file and run hashcat in mode -m 34000. Expect this to be slow — use a focused wordlist. Start with a wordlist such as rockyou.txt:

echo '$argon2id$v=19$m=65536,t=3,p=4$c29tZXNhbHQ$RdescudvJCsgt3ub+b+dWRWJTmaaJObG' > hash.txt && hashcat -m 34000 hash.txt /usr/share/wordlists/rockyou.txt

Add a rule set to mutate dictionary words (capitalisation, leetspeak, appended digits) and dramatically widen coverage:

echo '$argon2id$v=19$m=65536,t=3,p=4$c29tZXNhbHQ$RdescudvJCsgt3ub+b+dWRWJTmaaJObG' > hash.txt && hashcat -m 34000 hash.txt /usr/share/wordlists/rockyou.txt -r /usr/share/hashcat/rules/best64.rule

Cracking Argon2 with John the Ripper

John the Ripper can attack the same hash with the argon2 format:

echo '$argon2id$v=19$m=65536,t=3,p=4$c29tZXNhbHQ$RdescudvJCsgt3ub+b+dWRWJTmaaJObG' > hash.txt && john --format=argon2 --wordlist=/usr/share/wordlists/rockyou.txt hash.txt