CyberCheatsheets

Crunch Cheat Sheet

Generate custom wordlists from charset and length rules.

Passwords & CrackingcharsetgeneratormaskswordlistUpdated 2026-06-02

Overview

Crunch builds wordlists on the fly from character sets, length bounds, and pattern placeholders. Use it to create targeted lists for hashcat/John/Hydra instead of downloading multi-gigabyte generic dumps. Generated lists can be huge—plan disk space and scope.

Install

sudo apt install crunch
crunch -h
ls /usr/share/crunch/charset.lst

Essential commands

min max charset output

crunch 6 8 0123456789abcdef -o hex.txt

fixed length lowercase

crunch 8 8 abcdefghijklmnopqrstuvwxyz -o lower8.txt

pattern: @ = lower, , = upper, % = digit, ^ = special

crunch 8 8 -t ,@@^^%%% -o pattern.txt

Common workflows

Date-based passwords —

crunch 8 8 -t @@@@%%%% -o dates.txt    # 4 letters + 4 digits
crunch 10 10 -t summer%%%% -o summer.txt

Charset from file —

crunch 6 8 -f /usr/share/crunch/charset.lst mixalpha-numeric -o mix.txt
crunch 4 6 -f charset.lst numeric -o pins.txt

Pipe to another tool (no huge file) —

crunch 4 4 0123456789 | head -n 1000
crunch 6 6 abcdefghijklmnopqrstuvwxyz | hashcat -m 1000 hashes.txt -

Split output —

crunch 8 8 abcdefghijklmnopqrstuvwxyz -o START -b 10mb -o START

Flags reference

min max

Length range

-o

Output file

-t

Pattern (@, ,, %, ^)

-f

Charset from .lst

-s

Start string

-c

Lines per file (split)

-b

Max size per file

-z

Compress (gzip/bzip/lzma)

Tips

  • Estimate size before generating: crunch 8 8 charset -s | tail (dry run options vary by version).
  • Combine with OSINT (company name, season) in -t patterns instead of full brute force.
  • For GPU masks, hashcat -a 3 is often faster than multi-terabyte crunch output.
  • @ lowercase, , uppercase, % number, ^ symbol in -t patterns.

References

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