Zelix KlassMaster
Zelix KlassMaster is a Java bytecode obfuscation tool intended to make reverse-engineered code less useful and protect applications from decompilation and re…
What Zelix KlassMaster is
Zelix KlassMaster is a Java bytecode obfuscation tool intended to make reverse-engineered code less useful and protect applications from decompilation and reverse engineering. It offers flow, exception, name, reference, method-parameter, string, integer, and long obfuscation or encryption. Name obfuscation shortens package, class, field, and method names, while Trim removes unused classes, fields, and methods. The product includes a GUI and build-tool interface, and ZKM Script can automate obfuscation in a build cycle. AutoReflection handles complicated Java Reflection API calls; Smart Save helps manage JARs, resources, and Enterprise Java Beans deployment descriptor files. Zelix says it can process bytecode compiled for Java 1.1 through Java 27, including modules, and that the Java-based product should run on systems with a Java 8 or later virtual machine. It lists Windows, Linux, and macOS as tested environments, and describes Android support as obfuscating Java class files before APK conversion. A commercial license is perpetual and covers one computer. Prices listed include $290 per license, once, for Small Developer and $585 per license, once, for Standard. A 30-day evaluation is available, but evaluation flow obfuscation is limited to one or two methods per class.
Good
- Offers several obfuscation and encryption methods.
- ZKM Script can automate build-cycle obfuscation.
- Includes a GUI and build-tool interface.
- Processes Java bytecode, including modules.
- Supports Android class-file obfuscation before APK conversion.
Watch out
- No free plan is listed.
- Evaluation flow obfuscation affects only one or two methods per class.
- Standard commercial licenses cover one computer.
Who it suits
Zelix KlassMaster may suit developers protecting Java applications or adding obfuscation to a build process. Its listed Android support is for Java class files before APK conversion.
Verdict
Zelix KlassMaster combines a wide range of Java bytecode transformations with scripting and build interfaces. Check the license terms and evaluation limits against your deployment needs before purchasing.
Plans and prices
From Zelix KlassMaster's own pricing page, checked 9 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Small Developer | $290, paid once | One machine · organization of no more than two people, including employees or contractors in the prior 12 months · Per license |
| Standard | $585, paid once | One machine · organizations of three or more people, or with three or more employees or contractors in the prior 12 months · Per license |
| 2 machine multi-license | $1,025, paid once | 2 machines · Per license purchase |
| 3 machine multi-license | $1,318, paid once | 3 machines · Per license purchase |
| 4 machine multi-license | $1,610, paid once | 4 machines · Per license purchase |
| 5 machine multi-license | $1,900, paid once | 5 machines · Per license purchase |
| Site license | $2,195, paid once | Any number of machines at one physical location · Per license purchase |
The facts
Each one read from Zelix KlassMaster's own pages, with the date it was checked.
Where it runs
- Android
- The FAQ says Zelix KlassMaster supports Android by obfuscating Java class files before they are converted into an APK.checked 9 Oct 2026
- Runtime platforms
- The vendor says the Java-based product should run on platforms with a Java 8 or later virtual machine and lists tested Windows, Linux, and macOS environments.checked 9 Oct 2026
What it does
- Automation
- ZKM Script can automate obfuscation and integrate it into a build cycle, and the product also has a GUI and build tool interface.checked 9 Oct 2026
- Build integrations
- The vendor provides a basic Gradle plugin and documents calling Zelix KlassMaster through a generic Java API; newer Gradle versions may cause failures due to bytecode instrumentation.checked 9 Oct 2026
- Evaluation limit
- The evaluation license is for one computer and 30 days, and the evaluation version flow-obfuscates only one or two methods in each class.checked 9 Oct 2026
- Java compatibility
- The product can process bytecode compiled for Java 1.1 through Java 27, including modules.checked 9 Oct 2026
- License terms
- A standard commercial license is perpetual, non-exclusive, and non-transferable for use on one computer.checked 9 Oct 2026
- Obfuscation features
- Features include flow, exception, name, reference, method parameter, string, integer, and long obfuscation or encryption.checked 9 Oct 2026
- Privacy and security
- The privacy policy says Zelix uses reasonable measures to protect personal information but cannot guarantee absolute security; it also says it does not sell or rent personal information.checked 9 Oct 2026
- Purpose
- Zelix KlassMaster obfuscates Java code to make reverse engineered source code less useful and protect it from decompilation and reverse engineering.checked 9 Oct 2026
- Reflection and packaging
- AutoReflection handles complicated Java Reflection API calls, and Smart Save simplifies handling JAR, resource, and Enterprise Java Beans deployment descriptor files.checked 9 Oct 2026
- Size reduction
- Name obfuscation reduces package, class, field, and method name sizes, while Trim removes unused classes, fields, and methods.checked 9 Oct 2026
- Support
- Technical support directs users first to the FAQ and online documentation, then to email support with product version, JVM, operating system, and error details where applicable.checked 9 Oct 2026
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