Netflix recently announced it had optimised its Android and iOS apps for mobile viewing, in an effort to save mobile data consumption.
The streaming service dynamically alters its content’s bit rate, depending on the motion in each segment of a video – saving users a lot of data.
We previously tested this claim, and Netflix’s statement that users can watch up to 26 hours of video with 4GB of mobile data.
Our finding was that 26 hours of mobile streaming would use around 5.3GB of data.
This test was conducted using a mobile data connection on a prepaid SIM – but would the data consumption change when the user is streaming content on Wi-Fi?
To find out, we conducted a data usage test under the same conditions as the mobile data test – watching Netflix on an Android smartphone – but this time used a Wi-Fi connection instead of mobile data.
The smartphone used for the test was a Nokia 5, which supports 2.4GHz and 5GHz Wi-Fi and has a screen resolution of 720 x 1,280.
We connected the device to a high-speed, stable Wi-Fi connection, before starting Netflix and watching a pair of shows.
Data usage was monitored using the MyDataManager app for Android, which delivers data consumption readouts for applications.
The Netflix account used for the test was set to automatically adjust streaming quality, and a speed test was conducted before streaming content to determine the device’s connection quality.
The MyBroadband Speed Test app was used for the speed measurements.
At the time the Netflix test started, the Nokia 5 scored Wi-Fi speeds of:
- Download – 33.76Mbps
- Upload – 9.51Mbps
We then played the first two episodes of The Expanse on Netflix, measuring data usage after each episode.
The streaming quality on the smartphone during the test was clear and smooth, and there was no buffering or skipping for the duration.
Two episodes of The Expanse were played during the test, each with a runtime of over 40 minutes.
The Wi-Fi data usage measured for each episode was substantially higher than the mobile data usage measured for the same episodes in the previous test, despite the similar download speeds and streaming quality.
A comparison of the mobile data results and the Wi-Fi data results is below.
|Data usage||Mobile data||Wi-Fi|
|Episode 1 (45m)||148MB||204MB|
|Episode 2 (43m)||153MB||177MB|
The discrepancy in data usage was suspected to be due to automatic mobile data usage settings in Netflix.
By default, Netflix automatically alters quality and data consumption based on a number of factors, including whether the user is connected to Wi-Fi or not.
Netflix confirmed to MyBroadband that its Android app detects whether the viewer is connected via mobile data or Wi-Fi, and adjusts data consumption and video quality accordingly.
When the Netflix app is set to the default “Automatic” data usage setting, it attempts to consume less data on a mobile connection.
“When on the automatic data usage setting, Netflix will select a data usage setting that balances data usage with good video quality,” said Netflix.
“Currently, this will allow you to watch about four hours per GB of data.”