Generate your seed on linux:

cat /dev/urandom |tr -dc A-Z9|head -c${1:-81}

Generate your seed on Mac:

Open Terminal and type or paste the following then press enter:

cat /dev/urandom |LC_ALL=C tr -dc 'A-Z9' | fold -w 81 | head -n 1

Generate your seed online:

You can generate your seed online using this website https://ipfs.io/ipfs/QmdqTgEdyKVQAVnfT5iV4ULzTbkV4hhkDkMqGBuot8egfA

Warning

Be extremely careful when using online services. Keep your IOTA Seed Private and Secure, do not share this with anyone.