How to identify and crack an SHA-1 hash

SHA-1 is an raw / unsalted hash type. It is fast and typically unsalted, which makes weak passwords recoverable quickly on consumer GPU hardware. 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 SHA-1 entirely in your browser — your hash is never uploaded. A typical example looks like this:

5baa61e4c9b93f3f0682250b6cf8331b7ee68fd8

Cracking SHA-1 with hashcat

Save the hash to a file and run hashcat in mode -m 100. Start with a wordlist such as rockyou.txt:

echo '5baa61e4c9b93f3f0682250b6cf8331b7ee68fd8' > hash.txt && hashcat -m 100 hash.txt /usr/share/wordlists/rockyou.txt

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

echo '5baa61e4c9b93f3f0682250b6cf8331b7ee68fd8' > hash.txt && hashcat -m 100 hash.txt /usr/share/wordlists/rockyou.txt -r /usr/share/hashcat/rules/best64.rule

Cracking SHA-1 with John the Ripper

John the Ripper can attack the same hash with the raw-sha1 format:

echo '5baa61e4c9b93f3f0682250b6cf8331b7ee68fd8' > hash.txt && john --format=raw-sha1 --wordlist=/usr/share/wordlists/rockyou.txt hash.txt