iCloud: What is iCloud Notes?
You can use Notes on iCloud.com to capture a quick thought or save something important or interesting for later, and then view those notes in the Notes app on your iOS device or Mac. You can also use Notes on iCloud.com to view and edit notes you created on your iOS device or Mac, using a Mac or Windows computer.
Note: You can only use Notes on iCloud.com to work with notes stored in iCloud, not the notes in other accounts you may have, such as a Yahoo! or Google account. However, on your iOS device or Mac, you can set up Notes to use iCloud and other accounts.
If you’re using another iCloud feature, you can switch to Notes by clicking the feature’s name at the top of the iCloud.com window.
When working with Notes on iCloud.com, make sure you use a browser recommended in the Apple Support article System requirements for iCloud.
The first time you use Notes on iCloud.com, you may get a message that says you need an iCloud email address. If so, you haven’t set up iCloud Notes on your iOS device or Mac. Sign in to iCloud on your iOS device or Mac, then turn on Notes. The iCloud Notes features you have depend on the following:
If your device has iOS 9 or later or OS X 10.11 or later: You’re now using upgraded iCloud notes.
If your device has earlier versions of the iOS or OS X: You don’t have access to upgraded notes. Choose an iCloud email address for a free iCloud email account. This account will be used to store your iCloud notes.
Note: To use all iCloud Notes features, upgrade your iCloud Notes account and upgrade your devices so they use iOS 9 or later or OS X 10.11 or later. See the Apple Support article Upgrade your Notes app.