How to use NetGuard to block internet access app by app

¿How to use NetGuard to block internet access app by app? On Android, it's very easy for apps to connect to the internet even when you're not using them. This translates into a loss of privacy, rapidly draining battery, and data plans that disappear without you even noticing. The operating system offers some controls, but they are increasingly limited and, moreover, scattered across unintuitive menus.

Luckily, they exist Solutions like NetGuard, a non-root firewall that lets you decide app by app It controls what can and can't be shared online. It's a way to have "selective airplane mode": you block ads, avoid suspicious connections, and still receive your important messages, calls, and notifications without giving up anything.

Why block internet access for some apps

Many applications don't need constantly connected to the Internet to functionBut they do it anyway. In the background, they send usage statistics, tracking data, device identifiers, and even location information that isn't always essential for the app to do its job.

By selectively cutting off that connection with a tool like NetGuard You gain privacy, reduce ads, and have much better control over your data usageAnd all this without uninstalling apps or rendering your phone useless like when you activate full airplane mode.

One of the clearest reasons is the protection of your personal informationSome apps can record your location, Android ID, contacts, or browsing history to feed advertising profiles or, in the worst-case scenario, for opaque purposes. By limiting which apps have internet access, you prevent them from leaking this data.

There's also the issue of the intrusive ads and junk notificationsEspecially in free games and apps. Often, the only real reason these apps connect is to download banners, videos, and all kinds of advertising. If the app works perfectly offline, you can continue using it with a firewall… but without ads.

And let's not forget battery and mobile data consumption. Background connections, continuous syncing, and trackers constantly sending information all contribute to this. They drain your battery and can exceed your data limitespecially if you have a tight budget or are roaming.

Android limitations: why a firewall is necessary

For years, some Android mobile phone manufacturers included the option to Restrict internet access per app from SettingsHowever, since Android 11, many brands have removed or hidden this feature, and even recent versions of the system (such as Android 16) do not offer a clear and unified solution.

The most that Android usually offers out of the box is the option to limit background data For certain apps, or to block them when you're only using mobile data. That works as a workaround, but it's not a real firewall: some apps still connect when they're in the foreground, and the controls vary greatly depending on the manufacturer and the interface.

Furthermore, Google has been relaxing fine-grained control of permissions and network usageIn practice, if you want serious control over which apps connect, when, and why, you need a firewall. Traditionally, that meant rooting your device and using solutions that modified the system, with the risks and complications that entails.

This is where NetGuard comes in: a firewall that doesn't require root access and works through a local VPNAndroid only allows one active VPN at a time, so this approach has its drawbacks, but it also allows any user to control their apps' traffic without touching the system or unlocking the bootloader.

What is NetGuard and how does it actually work?

NetGuard is an application of Open source code that acts as a firewall for Android No root access is required. The trick lies in leveraging an API available since Android Lollipop that allows the creation of a local VPN. All network traffic from the device is routed through this "fake" VPN, and from there, NetGuard decides what to allow and what to block.

In practical terms, when you block an app with NetGuard, its traffic is redirected to a kind of internal “digital dump”It tries to connect, but the packets never actually leave your mobile device. This can apply to both Wi-Fi and mobile data connections, and you can choose to block one or the other separately, or both at the same time.

NetGuard's design is intended to be Easy to use even for someone who knows nothing about networksIt displays a list of all your apps, and next to each one, two icons: one for Wi-Fi and one for mobile data. The color of each icon tells you whether that app can connect or not, and you can change its status with a single tap.

Since it doesn't require root access, NetGuard doesn't modify system files or touch sensitive areas of the device. Compatible with virtually any modern Android mobile phoneProvided it allows the use of a VPN. Furthermore, by reducing the number of background connections, it often helps save battery power instead of draining it.

As an open-source project, its code is available for public auditing. This is key: If NetGuard did anything suspicious with your data, the community would detect it.This transparency greatly reduces the understandable fear that comes with giving an app the ability to see and filter all your traffic.

Advantages and main features of NetGuard

One of NetGuard's strengths is that It not only allows you to block user apps, but also many system apps.This is especially useful if you want to curb services that are very aggressive with advertising or telemetry, as long as you understand that blocking them may affect features like push notifications or updates.

In its free version, NetGuard offers a fairly comprehensive set of features: supports IPv4/IPv6, TCP and UDP protocolsIt supports tethering and can log and display data usage for each app. It can even show notifications when an app tries to access the internet, so you can decide on the spot whether to allow or block it.

Upgrading to the Pro version unlocks advanced options such as full log of all outgoing traffic per application, search and filtering of connection attempts, export of PCAP files for analysis with professional tools and the ability to allow or block specific addresses (IP or domains) per app.

Another important advantage is that NetGuard It tries to optimize the impact on the battery.By reducing unnecessary background connections and pointless synchronizations, battery life typically improves. The firewall itself doesn't consume much power if it's properly configured and excluded from some manufacturers' aggressive energy-saving features.

Furthermore, the interface allows you to configure behaviors based on the screen's state. For example, you can Allow internet access when the screen is on and block it in the background for certain apps. They function normally while you're using them, but stop using data and energy when you close them.

How to install and configure NetGuard step by step

The first step is Download NetGuard from Google Play or from its repository on GitHubBoth versions are legal and safe, but the one on the Play Store updates automatically, while from GitHub you can access versions that may be more recent or with specific features.

Once the application is installed, when you open it you will see a main switch at the topThat's the master button that turns the firewall on or off. The first time you activate it, Android will display a notification asking for permission to create a local VPN connection; you must accept this for NetGuard to function.

As soon as the VPN starts up, NetGuard begins to display all the applications installed on your device in a list. Next to each app's name, you'll see two icons: one with the Wi-Fi symbol and another with the mobile data symbol. Each icon may appear green (allowed) or orange/red (blocked), depending on the current settings.

With a tap on each icon, you decide whether that app can use that connection. For example, you can Allow access via WiFi but block mobile data a game that eats up your data allowance, or the opposite for a specific app. You don't need to go into the settings of each system application: everything is managed from this central screen.

If you tap the app name instead of the icons, a more detailed screen opens. From there you can fine-tune background behavior: allow it to connect only when the screen is on, block data usage with the screen off, or apply special conditions for that specific case.

Lockdown mode and other useful features

One of NetGuard's most powerful features is the so-called Lockdown mode or total traffic blockingBy activating it from the three-dot menu, the firewall will block all connections from all apps by default, except those you explicitly mark as allowed.

This approach is ideal if you want maximum control: instead of blocking app by app, You block parts of everything and then create exceptions. For your messaging, email, banking, or other apps that you really need to be connected. To enable an app in Lockdown mode, simply go to its details in NetGuard and select the "Allow in Lockdown mode" option.

Another interesting option is to add NetGuard to the Android quick settings panelFrom there you can enable or disable the firewall just like airplane mode or Wi-Fi, without having to open the app each time. It's very useful if you need to temporarily disable all restrictions.

NetGuard also has a connection log, which shows which applications are trying to connect, when, and to which destinationsReviewing this history is a very convenient way to detect suspicious apps that connect too often or to servers you didn't expect.

Finally, it is essential to exclude NetGuard from the systems of aggressive battery optimization which many manufacturers include. If the system kills the app in the background, the firewall will stop working without you noticing. When the "disable battery optimization" notification appears, it's worth following the steps and selecting the "Don't optimize" option.

Advanced tips and combination with other blockers

Although NetGuard can block a good portion of advertising by cutting off the connection of many apps, in some cases It is recommended to combine it with an ad blocker Additionally, this filters out both unnecessary connections and banners that are integrated into websites, games, or services that you do need to have access to the network.

Another good practice is to occasionally check the traffic history and NetGuard logs To identify applications that abuse internet access. If you see a simple game that connects every few minutes, it might be worth blocking it or even looking for a less intrusive alternative.

Screen state control also offers a lot of possibilities. You can configure certain apps, such as social networks or email clients, to take over. They only connect when the screen is on.This way you still receive content when you open them, but the constant trickle of data in the background is reduced.

If you use older versions of Android (for example, Android 10 or earlier), some manufacturers like Huawei or Chinese brands still include Internal settings to restrict mobile data and WiFi access per appIn those cases, you can combine those native controls with NetGuard for a double layer of protection.

In professional environments, with many devices that depend on strict policies, it may be worthwhile to consider MDM (Mobile Device Management) solutions like AirDroid Business or similar tools. These allow you to apply network restrictions, block apps, or limit their usage centrally, without having to configure each device individually. If you're still interested in learning more about this, we've included this article about What to do in the first 24 hours after a hack: mobile, PC and online accounts

Disadvantages, limitations, and compatibility with other VPNs

Although NetGuard is very powerful, it's important to be aware of its limitations. limitations before launching into reckless blockingThe most important limitation is that Android only allows one active VPN at a time. Since NetGuard works by creating a local VPN, you won't be able to use another VPN app (such as WireGuard or similar) simultaneously.

This creates a conflict for those who want to have both. an application firewall as a real outbound VPN (For example, to encrypt internet traffic or change your country). In these cases, you have to choose: either use NetGuard or use your traditional VPN. Alternatively, there are projects like RethinkDNS that attempt to combine both functions into a single app.

Another relevant limitation is that NetGuard It cannot control all system apps 100%.Some critical Android services, such as the download manager or certain components of Google Play Services, may continue to connect even if you block them, as the system itself treats them as part of the core.

This means you may still see any advertising or traffic originating from system componentsEven with NetGuard enabled. There are also apps that rely on Google Play Services to display ads, notifications, or sync, and blocking those services can cause legitimate apps to malfunction.

Finally, if you block internet access too aggressively, some apps may malfunction. limited functionality, login failures, or update problemsIt's key to find a balance: cutting off access to what you don't need, but allowing what's essential for applications to function properly and continue receiving security patches.

Alternatives and add-ons to NetGuard

Not everyone is comfortable with a VPN-based firewall, or needs compatibility with another VPN at the same time. In that scenario, some people look for... applications that adjust network permissions using system settingswith a more convenient interface than going app by app from Settings.

Tools like RethinkDNS attempt to fill that gap: They offer a kind of application firewall and secure DNS/VPN features. in the same app. Although they may not yet reach the level of detail of NetGuard Regarding filters based on screen status or advanced logging, they allow for simultaneous network protection and VPN tunneling without root access.

If your only concern is data usage and not so much privacy, Android's built-in settings for Limit background data and restrict mobile data usage They may be sufficient. They are more basic and less transparent, but they don't add another layer of complexity or depend on a VPN.

In any case, whether you choose NetGuard or try alternatives, the important thing is to be clear about the objective: reduce unnecessary traffic, protect your data, and improve the user experience instead of navigating blindly while apps do whatever they want in the background.

With a well-configured firewall tool and some good habits (checking permissions, being wary of apps that request access to everything, updating frequently), it's perfectly possible Enjoy Android with far fewer hassles, more privacy, and more battery life.Without needing root access or dealing with complicated configurations. Now you know. How to use NetGuard to block internet access app by app.