Bip39 Docs To create a seed phrase by doing this, You'll have a calculator that has a RANDOM purpose (for producing entropy). Learn more about making a seed phrase using an offline calculator in this article. BIP39 specifies a list of 2048 words from which the mnemonic phrase is decided https://immensedirectory.com/listings646177/free-seed-phrase-generator-with-balance-github-the-greatest-guide-to-bip39