macOS Sierra: Manage passwords using keychains
macOS uses keychains to help you keep track of and protect the passwords, account numbers, and other confidential information you use everyday on your Mac computers and iOS devices.
You can use the Keychain Access app on your Mac to view and manage your keychains. If you set up iCloud Keychain on your Mac, you can store your keychains in iCloud Keychain and access them from any of your Mac computers or iOS devices.
What is a keychain?
A keychain is an encrypted container that securely stores your account names and passwords for your Mac, apps, servers, and websites, and confidential information, such as credit card numbers or bank account PIN numbers.
When you access a website, email account, network server, or other password-protected item, you can choose to save the password in your keychain so you don’t have to remember or enter the password each time.
Each user on a Mac has a login keychain. The password for your login keychain matches the password you use to log in to your Mac. If an administrator on your Mac resets your login password, you’ll need to reset your login keychain password.
You use the Keychain Access app on your Mac to view and manage your login and other keychains, and also the items securely stored in the keychains—for example, keys, certificates, passwords, account information, and notes. If you forget a password, you can find it in Keychain Access. Learn more about Keychain Access.
If you use iCloud, you can have iCloud Keychain securely store your Safari website user names and passwords, credit card information used online, Wi-Fi network information, and more. iCloud Keychain automatically keeps that information up to date across all your Mac computers and iOS devices. iCloud Keychain also stores login information for the accounts you use in Mail, Contacts, Calendar, and Messages—and in social media accounts like Facebook or Twitter—so they’re available on all your devices. Learn more about iCloud Keychain.
Tip: When you use passwords and credit cards online, you can let Safari store them in your keychain and automatically fill them in for you. If you also use iCloud Keychain on your Mac and iOS devices, Safari can fill in the stored information on any of them. For more information, see Use AutoFill to enter contact info, passwords, and more.