Proguard and Their Implications on Android Application


Modern applications are prone to a wide range of security threats. This has compelled developers to adopt the best practices to prevent attacks. Less than 50 % of financial apps on the Android marketplace are known to have proper security measures installed. This means that the apps could become victims including IP theft, sensitive data loss, and among others, reputational damage.

Another thing that you need to take into account is the performance of an app. The moment you remove unnecessary applications and elements the apps turn out to be faster and smaller. Code obfuscation is important when it comes to open-source- applications. There are numerous tools for Android Studio that facilitate code obfuscation such as Proguard Android. It is better that you know about the details

Features of Proguard

Proguard is critical to reducing the app size and optimize the applications.. Shrinking, optimization, obfuscation and pre-verification are important features of Progaurd which blocks reverse engineering methods. Not only does it reduce the size of the app but contributes to better performance to a considerable extent. Let us understand about these features in a nutshell.


Shrinking refers to the reduction of the app size. By using Proguard it enables the detection of unused variables, methods and classes. The unused codes are removed from the applications and the libraries. Shrinking is achieved in a couple of ways

  • Code shrinking- Removal of unused classes, libraries and attributes from an application along with their dependencies that refer to code shrinking.
  • Resource shrinking- removing unused resource files from an application with its library dependencies upon resource shrinking.


Optimization refers to optimizing the by-code. Unused instructions could hurt the performance of an app. Redundant instructions in a small segment of the generated code are eradicated through peephole optimization methods. At this stage duplicate code is removed and the instructions may be replaced with shorter instructions that are identified and removed.


This is the process where you make the code unable to be read. An example is that a third party who has gained access to the code will not be able to derive any sense. Once you remove the unused codes the remaining classes, and methods are renamed using random characters. The reason why obfuscation turns out to be beneficial is that it hides the original intent of the code segment from the hackers.

The Benefits of Implementing Proguard

Progaurd is an open-source tool that is recommended for Android applications. It reduces the readability of a code which goes on to enhance the security of the applications. Apart from enhancing security, it is known to shrink applications to deliver a complete package. Below are some of the benefits of using Proguard in your applications.

Compact Configuration

ProGuard is expected to have a template-based configuration when you compare it with other Java Obfuscators. This works out to be one of the major benefits of Progaurd. With a simple configuration line or a few command line options, you can enable Proguard.

Protection against Static Analysis

Hackers are known to use static analysis to access the source code of your application. Once you use static analysis the hackers can access the source code of an app and control flow. This is going to give you an idea of how the app works without running the code. Proguard can shield the app from decompiles.

Reverse Engineering is a Tough Option

Once you apply relevant Proguard rules the concept of reverse engineering becomes difficult. Proguard shrinks the code and obfuscates with obscure names. Critical data may be exposed and leaked if hackers gain access to these applications. In addition, the obfuscation capabilities may serve as a hindrance to reverse engineering attempts.

Specifies the Dead Code

Proguard is able to identify the dead code that an application is no longer using. It also enables them to remove from the source code.

Reducing the Size of the Applications

Once you are using Progaurd it leads to smaller APK and AAB files. Progaurd is known to reduce the application size by 20 % to 90 %, It discards the unused codes and resources from your application with library dependencies resulting in a comprehensive package with smaller memory footprints.

Another important advantage of Proguard is that it can possess several megabytes within a few seconds. It is also known to provide an optimal user interface and plugins for ANT and JME Wireless Toolkit.

The Things to Observe about Proguard

Though the benefits of Proguard are numerous still there are a few pointers that one should be aware of. It may be great to start a mobile app security but it is something that has to be applied in conjunction with other security measures. Merely depending upon the same is not recommended.

In case of misconfiguration, the app may crash. If there are such negative impacts the outcome may not be the same. Once you apply Proguard it does not mean that your application is inaccessible by the hackers. There could be certain parts of the application that may be still prone to attacks.

There may be a situation that requires an additional form of testing. Progaurd is known to be using name obfuscation methods to rename the classes. To conclude most developers, end up using Proguard for their obfuscation capabilities. But you need to be aware that the benefits are not only restricted to the security aspect of it.

Progaurd is known to reduce the size of an app to a considerable extent. The reason is that it discards the unused codes and renames the classes or the characters to random characters. Hackers can access information about back-end servers, and ciphers and can perform code obfuscation.

This is once you are successful with reverse engineering and it provides protection from static analysis. Though it is fair to say that it is not going to provide you with complete protection from hackers, it is going to discourage them. This ensures that the applications are tough to reengineer.