Your team runs a SAST scan on every commit and a DAST scan before release. The dashboard is green. Yet the app heading to the App Store has never been tested the way an attacker will actually approach it. This is the gap that catches DevSecOps teams who carry web testing habits into mobile.
SAST, DAST, and MAST often get treated as three competing products. They are not. Two of them are testing methods. The third is a discipline built specifically for mobile. Getting the difference right decides whether your APK or IPA is genuinely covered or only looks covered on a report.
This guide is for DevSecOps and security engineers who want a clear, mobile specific answer, not a recycled web app explainer.
SAST, DAST, and MAST in one line each
- SAST reads the app without running it. It inspects source code and the compiled binary for flaws.
- DAST tests the app while it runs. It watches behaviour, network traffic, and how the app handles data live.
- MAST is the mobile specific practice that applies both methods to mobile artifacts, the APK and IPA, plus checks that only matter on a phone.
What does SAST check in a mobile app?
Static application security testing analyses code at rest. Nothing executes. A mobile SAST tool works in two modes. It can scan your source in Kotlin, Java, Swift, or a cross platform framework. It can also perform mobile app binary analysis, decompiling an APK or IPA when you only have the shipped package and no source.
What a mobile app static analysis tool catches well:
- Hardcoded API keys, tokens, and credentials in code or resource files
- Insecure local storage patterns, such as sensitive data in SharedPreferences or a misused iOS Keychain
- Weak or outdated cryptography calls
- Risky configuration, like exported components or a debug flag left on in the Android manifest
SAST runs early and cheaply, which is why it belongs on every commit and every build.
What does DAST check in a mobile app?
Dynamic application security testing runs the app and observes it. For mobile that means installing the build on a device or emulator and watching how it behaves under real conditions.
What DAST catches that SAST cannot:
- Cleartext traffic and broken TLS, including a missing certificate pinning check
- Sensitive data written to disk or logs at runtime
- Weak authentication and session handling in live flows
- How the app responds to tampering, rooting, or jailbreaking
DAST runs later, against a working build, usually in staging before release.
So where does MAST fit?
Here is the part most articles miss. MAST is not a third scanner competing with the other two. Mobile application security testing is the discipline that applies static and dynamic techniques to mobile, and adds the checks a web focused tool never performs.
A web SAST tool pointed at an APK does not understand the Android manifest, the permission model, or how iOS sandboxes data. A mobile aware approach does. It treats the APK and IPA as first class artifacts, maps every finding to the OWASP MASVS standard, and produces the evidence an auditor expects.
Put simply, SAST and DAST are methods. MAST is how those methods are done properly for a phone.
SAST vs DAST vs MAST: the comparison
| Method | What it inspects, and when | Artifact tested | MASVS groups best covered |
| SAST | Code at rest, no execution. Runs early, on commit and build. | Source code in Kotlin, Java, Swift, or cross platform, and the decompiled APK or IPA binary | STORAGE, CRYPTO, CODE, and parts of PLATFORM |
| DAST | The running app, live behaviour and traffic. Runs later, in staging. | The installed build on a device or emulator, plus live network traffic | NETWORK, AUTH, RESILIENCE, and runtime STORAGE |
| MAST | The mobile discipline that applies both methods, plus mobile only checks. Runs continuously, ideally in CI/CD. | APK and IPA as primary artifacts, alongside source and runtime | All eight MASVS groups when done in full |
When do you need all three?
For a simple internal app, static analysis on every build is a reasonable floor. For anything that handles money, identity, or health data, you need the full set.
- SAST for code level flaws, early and often.
- DAST for runtime and network behaviour before release.
- The mobile specific layer to tie both to your APK or IPA and to MASVS, so the result is audit ready.
Regulated teams in the UAE, GCC, and India rarely have a choice. NESA, RBI, and PCI DSS 4.0 expect documented testing and a clear evidence trail, which means coverage across all three, not one green dashboard.