A bug in the backup function of WhatsApp has caused a huge increase in cellular data usage for some users. The backup bug caused WhatsApp to upload huge amounts of data to the cloud, unfortunately in some case also when only a mobile network was available.
(WhatsApp uploading large backup – Credits: Gagan Rajput on Twitter)
WhatsApp allows users can choose how they want to store backups. Normally it’s not an issue when users allow the app to make backups over a mobile network, as WhatsApp only sends the most recent changes to the cloud, and because users can set the app to skip large content such as photos and videos.
However, various users now report that the backup feature is acting strange. Smartdroid reports how WhatsApp suddenly sent a gigabyte of data to the cloud. And even worse, when there was an issue with the connection, Whatsapp restarted the backup and wanted to uploaded twice as much data.
Other users report similar issues. Some of them discovered that WhatsApp uploaded gigabytes of data to the cloud. One user reports that WhatsApp tried to upload 14 GB of data to the cloud when on a cellular network.
Depending on the mobile provider, users are charged for overuse or their connection is throttled for the rest of the month. On fast mobile connections, such as LTE, the uploads will be hardly noticeable as a gigabyte of data can be transferred in less than a minute.
It’s unclear what causes the backup issues, initially it was thought only beta users were affected. But after reports of users who are not part of the beta program this doesn’t seem to be the case.
Users who want to be sure that WhatsApp doesn’t consume their entire data bundle should temporarily disable the backup feature. At least until the cause is known and the issue is resolved.