Wi-Fi Assist, a new feature in iOS 9, was initially met with some skepticism as Apple did a lousy job detailing how it works beyond stating that Wi-Fi Assist automatically uses cellular data when Wi-Fi connectivity is poor.
“With Wi-Fi Assist, you can stay connected to the Internet even if you have a poor Wi-Fi connection,” the iPhone maker said somewhat critically.
However, inexperienced users might encounter some unwanted effects when using their devices in areas with low Wi-Fi signal because Wi-Fi Assist will activate their carrier’s mobile data network and therefore possibly lead to increased data consumption and unwanted overage fees on the wireless bill.
Here’s what Apple is saying how Wi-Fi exactly works.
“Because you’ll stay connected to the Internet over cellular when you have a poor Wi-Fi connection, you might use more cellular data,” cautions the firm.
“For most users, this should only be a small percentage higher than previous usage,” reads Apple’s support document.
What apps are compatible with Wi-Fi Assist?
Most first and third-party apps (but not all, see further below for more info) work with Wi-Fi Assist enabled. Stock apps like Safari, Apple Music, Maps, Mail and more will try to use Wi-Fi Assist if iOS detects very slow or unreliable Wi-Fi connection.
“For example, if you’re using Safari with a poor Wi-Fi connection and a webpage doesn’t load, Wi-Fi Assist will activate and automatically switch to cellular so that the webpage continues to load,” states the company.
Is Wi-Fi Assist enabled by default?
Yes, Wi-Fi Assist is on by default. As mentioned, those on a metered data plan might want to disable Wi-Fi Assist unless they are OK with their iPhone staying connected to the Internet via mobile data when Wi-Fi is in an extremely weak state.
Full tutorial: How to enable and disable Wi-Fi Assist
You can disable Wi-Fi Assist by going to Settings → Cellular (or Settings → Mobile Data and flipping the Wi-Fi Assist button at the bottom to the OFF position.
What about roaming?
Thankfully, Apple’s wisely designed Wi-Fi Assist to ensure that it doesn’t automatically switch to your carrier’s cellular network when you’re data roaming.
Does Wi-Fi Assist use cellular data for background processes?
No, and that’s by design. Apple states that the feature only works when you have apps running in the foreground and doesn’t activate with background downloading of content.
What about apps that gobble up large amounts of data?
To further optimize cellular data consumption, Wi-Fi Assist won’t kick into action when certain audio and video-streaming apps attempt to use large amounts of data. It will also prevent downloading of attachments in email apps.
What devices does Wi-Fi Assist support?
Wi-Fi Assist is supported on any iPhone from the iPhone 5 and onward. On cellular-enabled iPads, Wi-Fi Assist will work on any model with iOS 9 or later except for the cellular-capable iPad 2, third-generation iPad and the original iPad mini.
As for iPod touches, Apple’s media player lacks cellular connectivity and as such won’t expose the Wi-Fi Assist switch in mobile data settings.
How can I tell if Wi-Fi is active?
When Wi-Fi Assist is enabled and iOS detects a poor Wi-Fi signal, the feature is automatically activated. You will know that Wi-Fi Assist has activated when the status bar turns gray before one of the symbols for cellular data appear.
You can read more about Wi-Fi Assist in our article here.