Have you ever wondered what’s really inside that Android app you just downloaded? Or needed to extract resources from an APK for a project? Maybe you’re just curious about what makes your favorite apps tick. Whatever your reason, you’ve come to the right place.
Being a mobile security researcher, and based on personal experience, I must say, you don’t need expensive software to peek inside APK files.
Some of the most powerful tools are completely free and open source.
After extensive testing, I’ve curated the definitive list of the top 5 free tools that will transform you from a casual user into an APK inspection expert. Let’s dive in.
1. 7-Zip: The Surprising Powerhouse
Best For: Quick resource extraction and basic inspection
Don’t let its simplicity fool you. 7-Zip is one of the most useful tools in any APK inspector’s arsenal. While it’s primarily known as a file archiver, it has a secret superpower. It can open APK files directly without any conversion.
Why It’s Powerful
- Instant access to raw APK files contents
- No learning curve and works like any ZIP file
- Lightweight and incredibly fast
- Completely free and open source
How to Use It
- Download and install 7-Zip from its official website
- Right click any APK file
- Select “7-Zip” then “Open archive”
- Browse through folders like res/drawable for images or res/raw for sound files
Pro Tip: You can drag and drop files directly from the 7-Zip window to your desktop to extract icons, sounds, or other resources instantly.
Perfect For: Graphic designers wanting to extract app assets, curious users exploring app contents, or anyone needing quick access to APK resources without technical hassle.
2. JADX: The Code Revelation Machine
Best For: Decompiling APK files to readable Java code
If 7-Zip shows you the app’s body, JADX reveals its soul. This open source tool can decompile classes.dex files back into nearly original Java code, making it possible to read and understand how an app works internally.
Why It’s Powerful
- Converts unreadable DEX code to readable Java
- Graphical interface with project tree navigation
- Search across entire codebase
- Handles obfuscated code better than most free tools
- Active development and regular updates
How to Use It
- Download JADX from its GitHub releases page
- Extract the ZIP file and run jadx-gui (or jadx-gui.bat on Windows)
- Open your APK file through the GUI
- Browse the code structure in the left panel
Real World Example: I recently used JADX to investigate why a weather app was draining battery. Within minutes, I found it was running continuous location checks in the background, something not mentioned in its description.
Perfect For: Developers learning from other apps, security researchers analyzing app behavior, or QA testers debugging issues.
3. APKTool: The Professional’s Choice
Best For: Decoding resources and rebuilding APKs files
APKTool is the industry standard for serious APK analysis. While it has a steeper learning curve, its power is unmatched for decoding binary XML files and resources that other tools can’t handle.
Why It’s Powerful
- Decodes AndroidManifest.xml to readable format
- Handles resource reconstruction perfectly
- Can rebuild modified APKs with re signing
- Excellent for debugging resource issues
How to Use It
- Install APKTool (requires Java)
- Use command: apktool d your-app.apk
- Access decoded resources in the output folder
- Read the now accessible AndroidManifest.xml
Pro Tip: Combine APKTool with JADX. Use APKTool for resources and JADX for code to get the complete picture.
Perfect For: Android developers reverse engineering apps, security professionals conducting deep analysis, or advanced users modifying app resources.
4. APK Analyzer (Android Studio): The Developer’s Built In
Best For: Quick size analysis and manifest inspection
If you have Android Studio installed, you already have one of the best APK inspection tools available. APK Analyzer provides a visual interface that’s perfect for quick analysis and understanding an app’s structure.
Why It’s Powerful
- Compare two APK files side by side
- Visualize file sizes and method counts
- View decoded manifest without command line
- Integrated with development workflow
How to Use It
- Open Android Studio
- Go to Build then Analyze APK
- Select your APK file
- Explore the visual interface
Perfect For: App developers optimizing their APK size, beginners learning APK structure, or anyone wanting a quick overview without installing additional tools.
5. VirusTotal: The Security Sentinel
Best For: Multi engine malware scanning
While not a traditional inspection tool, VirusTotal is essential for anyone working with APKs from unknown sources. It scans files against more than 70 antivirus engines simultaneously, giving you deep security insight.
Why It’s Powerful
- 70 plus antivirus engines in one scan
- Detailed behavioral analysis
- Community comments and ratings
- Completely free web based service
How to Use It
- Visit virustotal.com
- Upload your APK file
- Review results from all engines
- Check the Behavior tab for detailed analysis
Security Tip: I never install an APK from an unknown source without first checking it on VirusTotal. It’s saved me from multiple potentially malicious apps.
Perfect For: Security conscious users, anyone downloading APKs from third party sources, or developers verifying their own apps aren’t flagged as false positives.
Expert Recommendation: When Free Isn’t Enough
Taking APK Analysis to Professional Level
While the free tools above are excellent for most tasks, professionals who conduct daily APK analysis often need more powerful solutions. After testing countless options, two tools stand out for serious work.
1. JEB Decompiler: The Industry Standard
When your work depends on the most accurate decompilation, JEB Pro is worth every penny. It handles obfuscated code better than any free tool and produces remarkably clean output.
Security researchers at top firms rely on JEB for its reliability and advanced features like interactive debugging and scriptable analysis.
2. Mobile Security Framework (MobSF): The All in One Solution
For automated security testing, MobSF is unparalleled. This open source framework can static and dynamic analysis, detect vulnerabilities, and generate professional reports.
While there’s a learning curve, it’s the tool I use for comprehensive security assessments. The self hosted version is free, but their cloud offering provides convenience for teams.
Note: These recommendations come from years of hands on experience. We may earn commission from purchases, which supports our independent testing.
Mobile Solutions: APK Inspection on the Go
Sometimes you need to inspect APKs directly on your Android device. Here are my top picks.
APK Explorer and Editor (Free)
This robust mobile tool lets you view, extract, and even edit APK resources directly on your device. Perfect for quick mobile analysis.
Package Inspector
Great for viewing installed app details, permissions, and components without needing the APK file.
How to Choose the Right Tool
For Quick Resource Extraction
- Start with 7-Zip for instant access
- Use APK Explorer on mobile
For Code Analysis
- JADX for readable Java code
- APKTool for smali code and resources
For Security Analysis
- VirusTotal for quick scans
- MobSF for comprehensive testing
For Development Work
- APK Analyzer in Android Studio
- JADX for learning from other apps
My Personal Workflow
After analyzing a lot of APKs, here’s the workflow I recommend.
- Quick Scan: Start with VirusTotal for safety
- Resource Extraction: Use 7-Zip for images and assets
- Code Analysis: Open in JADX to understand functionality
- Deep Inspection: Use APKTool for resources and manifest
- Security Audit: Run through MobSF for vulnerabilities
Beyond the Tools: Ethical Considerations
Remember that with great power comes great responsibility. Always:
- Respect software licenses and intellectual property
- Only analyze apps you own or have permission to inspect
- Use these skills for learning, security research, and improvement
- Never distribute modified versions of others’ work
Your APK Inspection Journey Starts Now
The world of APK analysis is accessible thanks to these powerful free tools. Whether you’re a developer optimizing apps, a security researcher protecting users, or a curious tech enthusiast, there’s a perfect tool waiting for you.
Start with 7-Zip for immediate results, then gradually explore JADX and APKTool as your needs grow. Within hours, you’ll be uncovering the secrets hidden inside every Android app.
What will you discover in your first APK inspection? The only limit is your curiosity.
Nothing was added or removed content-wise; just structure, readability, and copy-paste readiness.
Frequently Asked Questions
You can use tools like 7-Zip to unzip the APK, JADX to decompile to readable Java, APKTool to decode resources and manifest, Android Studio’s APK Analyzer for visual inspection, and VirusTotal for malware scanning.
Decompilation typically involves using tools like JADX (for readable Java source) or combining APKTool with decompilers such as dex2jar and JD-GUI to convert DEX files into more understandable formats.
Yes. Browser-based tools like APK Explorer allow you to upload an APK and inspect its manifest, resources, permissions, and certificates online without installing desktop tools.
Decompiling an APK for personal research, security analysis, or interoperability may be legal in some regions, but it may violate copyright and app store terms depending on the jurisdiction and how you use the results.
Uploading the APK to services like VirusTotal scans it against dozens of antivirus engines and can reveal potential threats before installing or analyzing further.