Switching this on will use your browser's local storage to store your progress and written words as you type for safekeeping in case you accidentally close or navigate away from the page. Your writing is only stored in your browser, on your machine, and does not leave it - I have no access to what you wrote and nor does the website this page is hosted on. It is not shared with any other sites in any way, and they can't access your words either.
Remember this is not a substitute for copy-pasting your words in another document - always remember to do that when you're done.
If you'd like to enable local storage, click OK, else click Cancel. To clear local storage later, switch this setting to Off.
Can you write 500 words in 5 minutes?
The Fifty Headed Hydra is a popular NaNoWriMo challenge. The definition below is taken from WikiWriMo:
Fifty Headed Hydra: write 500 words in 5 minutes. Named for a writing sprint during a Virtual write-in in which one of the NaNo interns wrote 500 words and the only words spelled correctly were "fifty headed hydra".