The easiest and maybe even safest way to make a backup is to keep it somewhere online. Just hide it into a crypto container before doing anything.
If you keep your seed phrase online, you are giving it less security because online is not secure. You have have your wallet to be an offline wallet or a hardware wallet and you keep the see phrase online, what is the point that the wallet is offline. The best you can do at least is to backup your seed phrase offline. Or probably you meant offline.