Zelix KlassMaster review
Deep Java obfuscation controls for teams protecting JVM applications.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Zelix KlassMaster is a desktop Java bytecode obfuscator for developers and organizations that need to make compiled applications harder to decompile and analyze. It targets Java bytecode for JVM versions 1.1 through 26, including Java modules, and runs on Windows, macOS and Linux. Its audience is teams protecting distributed Java applications, libraries and JAR-based deployments that need more than basic name renaming.
Pricing uses one-time licenses rather than a recurring subscription. The Small Developer license costs $265 and is for organizations with no more than two people; software is emailed electronically. The 1 Standard license costs $532, while 2 Standard licenses cost $931. The catalog also lists 3 Standard licenses, 4 Standard licenses, 5 Standard licenses and a Site license for use on any number of machines at one physical location. A 30-day evaluation license is available, and there is no free plan. For build workflows, ZKM Script automation and integrations with Apache Ant, Apache Maven and Gradle connect the obfuscator to established Java tooling.
The product’s main strength is the breadth of its Java-specific controls. Alongside package, class, field and method name obfuscation, it includes control-flow obfuscation, string literal encryption, integer and long constant encryption, reference obfuscation, method parameter changing, exception obfuscation and class trimming. AutoReflection handling addresses Java Reflection API calls, while Smart Save processes JARs and resources. Stack trace translation and line-number scrambling support post-obfuscation diagnostics. Teams seeking deep JVM protection and configurable build integration should consider it; teams wanting a free tier, a recurring cloud service or protection beyond Java bytecode should look elsewhere.
Zelix KlassMaster pros and cons
- Where it wins
- Control-flow, string, constant and reference obfuscation
- Supports Java bytecode from JVM 1.1 through 26, including modules
- Integrates with Ant, Maven and Gradle
- Where it doesn't
- No free plan; licensing is paid and one-time
- Desktop software with CLI-based build integration
- Pricing is not shown for every listed license tier
Zelix KlassMaster fact sheet, pricing and score →
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
Last updated · How we research and update