Explained: Absolute Best way to Limit Data on Android

Infopackets Reader Sam G. writes:

" Dear Dennis,

I work from home and also own an Android smartphone, which I use to communicate (via text messages) with friends and family. Because I am home all the time, I use WiFi on my phone instead of data. Therefore, I purchased a very cheap 'pay as you go' data plan for when I'm away from the office. The problem is that my data is being eaten away by apps on my phone whenever I'm on the go. I have tried disabling 'background data' on my Android phone to limit which apps can use data, but this is incredibly time consuming because each data permission is buried deep in the system, requiring me to tap on multiple screens and multiple settings just to manage a single app. This makes it extremely difficult to manage. Surely there must be an easier way to do this. What is the best way I can block or limit data on my smartphone? "

My response:

The absolute, sure-fire best way to manage data effectively and easily is to use a firewall app.

Here's what to look for:

• A good firewall app will let you manage both WiFi and data settings separately (on a per-app basis). In doing so, you could allow all traffic on WiFi and then restrict data to only a handful of apps - such as email and instant messages.
   
• A good firewall app will also allow you to manage / select all data apps or WiFi apps at once. For example, you could select all apps under the 'data' column and then disable them, then enable only the ones you want enabled. This is a thousand times easier than selecting each app - one at a time - and selecting "block" for the ones you want to block, considering you will likely want to block 99% of your apps from using data.
   
• A good firewall app will use a VPN to block or enable data instead of requiring root access to manage firewall rules.

Related: Need to extend your Wifi coverage at home or in the office? Read this: Explained: What is Mesh WiFi? vs Extender, Router?

My Choice for Blocking Data on Android Phones: NetGuard

Update 20181113: Previously I recommended using an app called "NoRoot Data Firewall", however the app seems to suffer from issues which causes extremely high CPU usage, then it crashes. As a result, the battery on my phone would die 30% in 30 minutes.

Instead, I suggest going with NetGuard. With this firewall, you don't need to "root" your phone. Rooting a phone means to 'break into' the phone and have super user / administrative access to operating system files that would normally not be accessible to a normal user. This is a security risk. Older firewalls required root access, however NetGuard does not.

The way that NetGuard works is through a local virtual private network (VPN), instead of requiring root access. Most people use VPN's to connect to the Internet in an encrypted manner to avoid being spied on by third parties, however this is not how the VPN works on the NetGuard. Instead, it redirects the data locally on the phone (through a VPN socket) and blocks connections to the outside world (for apps you specify) so that these apps don't use up your data plan. This is a very smart way to manage data without having to root the phone.

Another great feature of the NetGuard app is that it uses very little CPU power, which means it won't kill your battery. Once a firewall rule is set, it either allows or disallows communication and does not require any processing power to do so. Another great feature of NetGuard is that it does not contain any ads and is completely free!

For the record, NoRoot Data Firewall is built on Netguard's open source programming. The difference is that NoRoot Data Firewall isn't updated as often as Netguard is. Also, as I mentioed, NoRoot Data Firewall seems to suffer from bugs, so I'm not recommending it anymore.

How to Block All Mobile Traffic using NetGuard (by default)

The easiest way to manage this VPN Firewall is to block all mobile traffic by default, then select the ones you want individually.

To do so:

1. Download and install NetGuard.
    
2. Launch NetGuard; click the main menu (the 3 horizontal dots at the top right), then select Settings -> Defaults (white / blacklist).
    
3. Make sure that "Block Mobile" and "Apply when Screen on" are both enabled.
    
4. Go back to the "Settings" page and select "Advanced Options" and enable "Manage system apps".
    
5. Go back to the main screen and by default all the mobile apps should be blocked.
    
6. Double check that all system apps aren't using your Mobile data. Specifically, make sure you block Google (Play) Services and Android OS as these will eat your data like no tomorrow on mobile, even when WiFi is in use! With these two disabled and only Messenger and WhatsApp running on my phone (on data) I only use about 30 MB of data PER MONTH! The downside to blocking these apps is that you may not receive notifications as quickly unless you are on WiFi - so be aware.

Data Firewall for iOS / iPhones

From what I have read online, there are no firewall apps for iPhones (also thanks to the comment below). If anyone owns an iPhone and has a great method for reducing data, please feel free to comment below.

I hope that helps!

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About the author: Dennis Faas is the owner and operator of Infopackets.com. With over 30 years of computing experience, Dennis' areas of expertise are a broad range and include PC hardware, Microsoft Windows, Linux, network administration, and virtualization. Dennis holds a Bachelors degree in Computer Science (1999) and has authored 6 books on the topics of MS Windows and PC Security. If you like the advice you received on this page, please up-vote / Like this page and share it with friends. For technical support inquiries, Dennis can be reached via Live chat online this site using the Zopim Chat service (currently located at the bottom left of the screen); optionally, you can contact Dennis through the website contact form.