If you’re using the official Twitter client for iOS, please note that the app defaults to autoplay videos in your Twitter stream on both Wi-Fi and cellular. Video autoplay is a convenient feature by saving you an extra tap to play a video. But autoplay could be a concern due to likely excessive cellular data usage, and also it is a drain on battery life for video you do not want to watch. You can change the settings to autoplay videos while on Wi-FI only, or switch off autoplay altogether.
Select the “Me” tab at right bottom of Twitter for iOS. Tap on the gear icon next to your Twitter profile picture. On the pop up menu, select “Settings”.
Under the Settings page, scroll down to General section and tap the “Video autoplay” option.
The default setting for autoplay is “Use mobile data and Wi-Fi”. You have the option to “Use Wi-Fi only”, or switch off autoplay by selecting “Never play videos automatically”.
If you have more than one Twitter account setup in Twitter client, this settings change will apply to all of them.