The Facebook-owned platform has been testing the feature for iPhone X and newer devices in its TestFlight beta releases for some weeks now, but version 2.19.20 of WhatsApp, now on the App Store, makes Face ID available for all users with supporting iPhones.
When enabled, users need to use Face ID to unlock the WhatsApp app, but they can still reply to messages from notifications and answer calls when the app is locked.
To require Face ID to unlock WhatsApp, tap Settings -> Account -> Privacy -> Screen Lock and toggle on the Require Face ID switch. Users with a fingerprint sensing Home button on their iPhones will see an option to Require Touch ID instead.
With the Face ID/Touch ID toggle enabled, users will see some additional options appear below that allow them to activate the authentication requirement immediately, after one minute, after 15 minutes, or after one hour.
When the app is locked, if the iPhone fails to recognize a face or fingerprint, users can alternatively choose to enter their iPhone Passcode to open WhatsApp.
Elsewhere in this update, a smaller change means users can now download individual stickers in a sticker pack from the in-app sticker store, rather than having to download the whole pack. Just select a stickers pack, tap and hold the desired sticker, then tap Add to Favorites in the pop-up pane.
WhatsApp is a free download for iPhone available on the iOS App Store. [Direct Link]