For those that use mymonero.com, if the site were to fail or suddenly shutter, how would someone be able to easily recover their funds using the seed provided by the website?
By using this page, you can generate your private keys from the mnemonic (note that you can also see and back-up your keys directly from mymonero.com interface, when logged-in with the mnemonic), which is all you need to restore your address. I would suggest to anyone to download that page and keep it somewhere just in case the site would go down. Once you have the private spend key and private view key, you simply start the cli wallet like below:
monero-wallet-cli.exe --generate-from-keys <filename>
./monero-wallet-cli --generate-from-keys <filename>
This will create a new wallet from your keys and save it with the filename specified. You will be prompted for your password with which you want to encrypt the wallet, and then for your address and the 2 private keys. When you finish refreshing your wallet, you will see your actual balance.
The process for doing so is located here. This should ensure that if mymonero were ever to shutdown or fail suddenly, there is still a method for recovering funds using the official wallets.
You actually don't need to generate the keys via external software, or https://xmr.llcoins.net/, or save that page … You only need to make sure that record:
- the address,
- the view key, and
- the spend key.
They're easily accessible from within the MyMonero.com website itself, via "Account Details". I described the process in this question, which also explains how to use the wallet from within the Monero Wallet GUI.
I recommend anyone using MyMonero.com to do that. You kill 2 birds with 1 stone. Not only you have a backup method for the website, but also the flexibility to use the GUI on your desktop, or the website from your smartphone. Transactions performed via the GUI will obviously also be shown via MyMonero.com, and vice versa.