Downloads

ProGuard is written in Java, so it requires a Java Runtime Environment (JRE 1.4 or higher).

You can download the latest release (containing the program jar, the documentation you're reading now, examples, and the source code) from this location:

If you're still working with an older version of ProGuard, check out the summary of changes below, to see if you're missing something essential. Better look at the up-to-date on-line version if you're reading a local copy of this page.

The download section may also contain updates with sub-minor version numbers. These versions are typically released shortly after their parent versions, for applying emergency fixes. Please make sure to look at those if you are encountering any problems with recent releases.

Finally, there may be beta versions of upcoming releases. They may be of interest too, because they typically contain any less urgent bug fixes collected since the previous release.

Dec 2011

Version 4.7

• Added support for Java 7.
• Parsing unquoted file names with special characters more leniently.
• Added support for instance methods overriding class methods.
• Added removal of unused parameterless constructors.
• Added removal of empty class initializers.
• Added peephole optimizations for constant strings.
• Avoiding idle optimization passes.
• Improved removal of unused constants after obfuscation.
• Fixed removal of unused classes referenced by annotations.
• Fixed simplifying parameters of constructors that should actually be preserved.
• Fixed simplifying parameters of large numbers of similar constructors.
• Fixed exceptions in optimization of unusual obfuscated code.
• Fixed NullPointerException when specifying -keepclassmembers without specific class or class members.
• Fixed potential problems with mixed-case class name dictionaries when not allowing mixed-case class names.
• Fixed obfuscation of classes with EnclosingMethod attributes that don't specify methods.
• Fixed preverification of returning try blocks with finally blocks, inside try blocks, when compiled with JDK 1.4.
• Fixed sorting of interfaces containing generics.
• Fixed paths in shell scripts.
• Fixed filling in of text fields showing class obfuscation dictionary and package obfuscation dictionary from configuration in GUI.
• Worked around Oracle Java 6/7 bug #7027598 that locked the GUI on Linux.
• Updated documentation and examples.

Feb 2011

Version 4.6

• Added support for synthetic, bridge, and varargs modifiers in configuration.
• Added detection of atomic updater construction with constant arguments.
• Fixed merging of package visible classes.
• Fixed optimization of fields that are only accessed by reflection.
• Fixed optimization of read-only or write-only fields that are volatile.
• Fixed handling of side-effects due to static initializers.
• Fixed handling of bridge flags in obfuscation step.
• Fixed handling of super flag when merging classes.
• Fixed updating of variable tables when optimizing variables.
• Fixed removal of unused parameters with 32 or more parameters.
• Fixed incorrect removal of exception handler for instanceof instruction.
• Fixed inlining of methods with unusual exception handlers.
• Fixed optimization of unusual code causing stack underflow.
• Fixed keeping of constructor parameter names.
• Fixed unwanted wrapping of non-standard META-INF files.
• Fixed filtering of warnings about references to array types.
• Fixed overriding of warning option and note option in Ant task.
• Improved detection of file name extensions for canonical paths.
• Improved printing of seeds specified by -keep options.
• Improved printing of notes about unkept classes.
• Improved checking whether output is up to date.
• Updated documentation and examples.

Jun 2010

Version 4.5

• Added option -keepparameternames.
• -dontskipnonpubliclibraryclasses is now set by default. Added -skipnonpubliclibraryclasses as an option.
• Made processing independent of order of input classes to get even more deterministic output.
• Improved constant field propagation.
• Improved renaming of resource files in subdirectories of packages.
• Avoiding making fields in interfaces private.
• Optimizing exception handlers for monitorexit instruction.
• Reduced maximum allowed code length after inlining from 8000 bytes to 7000 bytes.
• Fixed missing warnings about missing library classes.
• Fixed shrinking of annotations with arrays of length 0.
• Fixed handling of -0.0 and NaN values when simplifying expressions.
• Fixed copying of exception handlers when simplifying tail recursion calls.
• Fixed optimization of introspected fields.
• Fixed simplification of unnecessary variable initializations.
• Fixed evaluation of subroutines in pre-JDK 1.5 code.
• Fixed updating of access flags in inner classes information.
• Fixed disabling of field privatization.
• Fixed invocations of privatized methods.
• Fixed updating of local variable debug information in optimization step.
• Fixed print settings without file name in GUI.
• Fixed field privatization setting in GUI.
• Fixed saving incorrectly quoted arguments in GUI.
• Fixed handling of regular expressions with only negators.
• Fixed unwanted wrapping of non-standard META-INF files.
• Fixed regular expression pattern for constructors in ReTrace.
• Updated documentation and examples.

Jul 2009

Version 4.4

• Added new peephole optimizations.
• Added option -optimizations for fine-grained configuration of optimizations.
• Added option -adaptclassstrings for adapting string constants that correspond to obfuscated classes.
• Added option -keeppackagenames for keeping specified package names from being obfuscated.
• Added option -keepdirectories for keeping specified directory entries in output jars.
• Extended options -dontnote and -dontwarn for fine-grained configuration of notes and warnings.
• Added option -regex in ReTrace, for specifying alternative regular expressions to parse stack traces.
• Extended renaming of resource files based on obfuscation.
• Improved inlining of constant parameters and removal of unused parameters.
• Avoiding bug in IBM's JVM for JSE, in optimization step.
• Avoiding ArrayIndexOutOfBoundsException in optimization step.
• Fixed configuration with annotations that are not preserved themselves.
• Fixed preverification of invocations of super constructors with arguments containing ternary operators.
• Fixed processing of unreachable exception handlers.
• Fixed merging of exception classes.
• Fixed repeated method inlining.
• Fixed inlining of finally blocks surrounded by large try blocks, compiled with JDK 1.4 or earlier.
• Fixed optimization of complex finally blocks, compiled with JDK 1.4 or earlier.
• Fixed obfuscation of anonymous class names, if EnclosingMethod attributes are being kept.
• Fixed obfuscation of inner class names in generic types.
• Fixed decoding of UTF-8 strings containing special characters.
• Fixed copying of debug information and annotations when merging classes.
• Fixed writing out of unknown attributes.
• Fixed updating manifest files with split lines.
• Updated documentation and examples.

Dec 2008

Version 4.3

• Added class merging.
• Added static single assignment analysis.
• Added support for annotation and enumeration class types in configuration.
• Refined shrinking of fields in case of unusual -keepclassmembers options.
• Added simplification of tail recursion calls.
• Added new peephole optimizations.
• Fixed optimization of unused variable initializations causing negative stack sizes.
• Fixed optimization of unusual initialization code causing NullPointerExceptions.
• Fixed optimization of half-used long and double parameters.
• Fixed processing of complex generics signatures.
• Working around suspected java compiler bug with parameter annotations on constructors of non-static inner classes.
• Fixed obfuscation of classes with inner classes whose names are preserved.
• Fixed access of protected methods in repackaged classes.
• Added options -classobfuscationdictionary and -packageobfuscationdictionary.
• Adapting more types of resource file names based on obfuscation.
• Extended warnings about incorrect dependencies.
• Added start-up scripts and build scripts.
• Updated documentation and examples.

Mar 2008

Version 4.2

• Refined data flow analysis in optimization step.
• Fixed handling of exceptions when inlining subroutines.
• Fixed inlining of incompatible code constructs between different java versions.
• Fixed computation of local variable frame size.
• Fixed optimization of infinite loops.
• Fixed optimization of subroutine invocations.
• Fixed optimization of floating point remainder computations.
• Fixed removal of unused parameters in method descriptors containing arrays of longs or doubles.
• Added undocumented java system properties maximum.inlined.code.length (default is 8) and maximum.resulting.code.length (defaults are 8000 for JSE and 2000 for JME), for expert users who read release notes.
• Fixed processing of generic types in Signature attributes in shrinking and optimization steps.
• Fixed processing of inner class names in Signature attributes in obfuscation step.
• Improved adapting resource file names following obfuscated class names.
• Fixed interpretation of package names in GUI.
• Fixed default settings for Xlets in GUI.
• Updated documentation and examples.

Dec 2007

Version 4.1

• Fixed shrinking of default annotation element values.
• Fixed optimization of invocations of methods in same class that are accessed through extensions.
• Fixed optimization of invocations of synchronized methods without other side-effects.
• Fixed optimization of some non-returning subroutines.
• Fixed handling of local variable debug information when inlining methods.
• Avoiding StackOverflowErrors during optimization of complex methods.
• Fixed obfuscation of potentially ambiguous non-primitive constants in interfaces.
• Fixed preverification of some code constructs involving String, Class, and exception types.
• The Ant task now allows empty <injars> and <libraryjars> elements.
• Updated documentation and examples.

Sep 2007

Version 4.0

• Added preverifier for Java 6 and Java Micro Edition, with new options -microedition and -dontpreverify.
• Added new option -target to modify java version of processed class files.
• Made -keep options more orthogonal and flexible, with option modifiers allowshrinking, allowoptimization, and allowobfuscation.
• Added new wildcards for class member descriptors: "***", matching any type, and "...", matching any number of arguments.
• Added support for configuration by means of annotations.
• Improved shrinking of unused annotations.
• Added check on modification times of input and output, to avoid unnecessary processing, with new option -forceprocessing.
• Added new options -flattenpackagehierarchy and -repackageclasses (replacing -defaultpackage) to control obfuscation of package names.
• Added new options -adaptresourcefilenames and -adaptresourcefilecontents, with file filters, to update resource files corresponding to obfuscated class names.
• Added detection of dynamically accessed fields and methods.
• Now treating Exceptions attributes as optional.
• Now respecting naming rule for nested class names (EnclosingClass$InnerClass) in obfuscation step, if InnerClasses attributes or EnclosingMethod attributes are being kept.
• Added new inter-procedural optimizations: method inlining and propagation of constant fields, constant arguments, and constant return values.
• Added optimized local variable allocation.
• Added more than 250 new peephole optimizations.
• Improved making classes and class members public or protected.
• Now printing notes on suspiciously unkept classes in parameters of specified methods.
• Now printing notes for class names that don't seem to be fully qualified.
• Added support for uppercase filename extensions.
• Added tool tips to the GUI.
• Rewritten class file I/O code.
• Updated documentation and examples.

• Since ProGuard now treats the Exceptions attribute as optional, you may have to specify -keepattributes Exceptions, notably when processing code that is to be used as a library.
• ProGuard now preverifies code for Java Micro Edition, if you specify the option -microedition. You then no longer need to process the code with an external preverifier.
• You should preferably specify -repackageclasses instead of the old option name -defaultpackage.

Dec 2007

Version 3.11

• Fixed optimization of invocations of methods in same class that are accessed through extensions.
• Fixed optimization of invocations of synchronized methods without other side-effects.
• Updated documentation and examples.

Aug 2007

Version 3.10

• Now handling mixed-case input class names when -dontusemixedcaseclassnames is specified.
• Fixed optimization of synchronization on classes, as compiled by Eclipse and Jikes.
• Fixed optimization of switch statements with unreachable cases.
• Avoiding merging subsequent identically named files.
• Updated documentation and examples.

Jun 2007

Version 3.9

• Fixed processing of .class constructs in Java 6.
• Fixed repeated processing of .class constructs.
• Fixed possible division by 0 in optimization step.
• Fixed handling of variable instructions with variable indices larger than 255.
• Updated documentation and examples.

Mar 2007

Version 3.8

• Fixed optimization of parameters used as local variables.
• Fixed obfuscation with conflicting class member names.
• Fixed incremental obfuscation with incomplete mapping file for library jars.
• Updated documentation and examples.

Dec 2006

Version 3.7

• Now accepting Java 6 class files.
• Fixed shrinking of partially used annotations.
• Improved incremental obfuscation, with new option -useuniqueclassmembernames.
• Printing more information in case of conflicting configuration and input.
• Fixed optimization of repeated array length instruction.
• Fixed optimization of subsequent try/catch/finally blocks with return statements.
• Fixed optimization of complex stack operations.
• Fixed optimization of simple infinite loops.
• Fixed optimization of expressions with constant doubles.
• Tuned optimization to improve size reduction after preverification.
• Fixed overflows of offsets in long code blocks.
• Now allowing class names containing dashes.
• Updated documentation and examples.

May 2006

Version 3.6

• No longer automatically keeping classes in parameters of specified methods from obfuscation and optimization (introduced in version 3.4).
• Fixed inlining of interfaces that are used in .class constructs.
• Fixed removal of busy-waiting loops reading volatile fields.
• Fixed optimization of comparisons of known integers.
• Fixed optimization of known branches.
• Fixed optimization of method calls on arrays of interfaces.
• Fixed optimization of method calls without side-effects.
• Fixed optimization of nested try/catch/finally blocks with return statements.
• Fixed initialization of library classes that only appear in descriptors.
• Fixed matching of primitive type wildcards in configuration.
• Fixed the boilerplate specification for enumerations in the GUI.
• Updated documentation and examples.

Jan 2006

Version 3.5

• Fixed obfuscation of class members with complex visibility.
• Fixed optimization bugs causing stack verification errors.
• Fixed optimization bug causing overridden methods to be finalized.
• Fixed optimization bug causing abstract method errors for retro-fitted library methods.
• Fixed optimization bug evaluating code with constant long values.
• Fixed bug in updating of optional local variable table attributes and local variable type table attributes after optimization.
• Fixed interpretation of comma-separated class names without wildcards.
• Updated documentation and examples.

Oct 2005

Version 3.4

• Extended optimizations: removing duplicate code within methods.
• Extended regular expressions for class names to comma-separated lists.
• Now automatically keeping classes in descriptors of kept class members.
• Added verbose statistics for optimizations.
• Added boilerplate Number optimizations in GUI.
• Fixed Class.forName detection.
• Fixed incremental obfuscation bug.
• Fixed optimization bug causing stack verification errors.
• Fixed optimization bugs related to removal of unused parameters.
• Fixed exception when optimizing code with many local variables.
• Fixed exception when saving configuration with initializers in GUI.
• Updated documentation and examples.

Jun 2005

Version 3.3

• Extended optimizations: making methods private and static when possible, making classes static when possible, removing unused parameters.
• Made file names relative to the configuration files in which they are specified. Added -basedirectory option.
• Added -whyareyoukeeping option to get details on why given classes and class members are being kept.
• Added warnings for misplaced class files.
• Improved printing of notes for Class.forName constructs.
• Implemented 'assumenosideeffects' nested element in Ant task.
• Improved processing of annotations.
• Fixed reading and writing of parameter annotations.
• Fixed various optimization bugs.
• Fixed wildcards not matching '-' character.
• Fixed wildcard bug and checkbox bugs in GUI.
• Setting file chooser defaults in GUI.
• Leaving room for growBox in GUI on Mac OS X.
• Properly closing configuration files.
• Updated documentation and examples.

Dec 2004

Version 3.2

• Fixed JDK5.0 processing bugs.
• Fixed optimization bugs.
• Fixed relative paths in Ant task.
• Improved speed of shrinking step.
• Updated documentation and examples.

Nov 2004

Version 3.1

• Improved obfuscation and shrinking of private class members.
• Added inlining of interfaces with single implementations.
• Added option to specify obfuscation dictionary.
• Added option to read package visible library class members.
• Extended support for JDK5.0 attributes.
• Fixed various optimization bugs.
• Modified Ant task to accept paths instead of filesets.
• Fixed two Ant task bugs.
• Updated documentation and examples.

Aug 2004

Version 3.0

• Added bytecode optimization step, between shrinking step and obfuscation step.
• Generalized filtered recursive reading and writing of jars, wars, ears, zips, and directories.
• Added support for grouping input and output jars, wars, ears, zips, and directories.
• Added support for applying mapping files to library classes.
• Removed -resourcejars option. Resources should now be read using regular -injars options, using filters if necessary.
• Rewrote Ant task. Input and output modification dates are not checked at the moment. Minor changes in XML schema:
  • Filters now specified using attributes.
  • 'outjars' now nested element instead of attribute.
  • 'type' attribute of <method> element no longer defaults to 'void'.
  • < and > characters now have to be encoded in embedded configurations.
  • <proguardconfiguration> task no longer accepts attributes.
• Updated J2ME WTK plugin, now customizable through configuration file.
• Updated GUI.
• Fixed various processing bugs.
• Fixed ReTrace parsing bugs.
• Improved jar compression.
• Updated documentation and examples.

Mar 2004

Version 2.1

• Added support for JDK1.5 classes.
• Added additional wildcard for matching primitive types.
• Added possibility to switch off notes about duplicate class definitions.
• Fixed use of multiple filters on output jars.
• Fixed option to keep all attributes.
• Fixed various Ant task bugs.
• Updated documentation and examples.

Dec 2003

Version 2.0

• Added a graphical user interface for ProGuard and ReTrace.
• Added -applymapping option for incremental obfuscation.
• Added support for filtering input and output files.
• Added support for the J++ SourceDir attribute.
• Improved detection of .class constructs.
• Improved handling of misplaced manifest files.
• Improved implementation of ReTrace.
• Worked around String UTF-8 encoding bug affecting foreign characters.
• Fixed exception when ignoring warnings.
• Fixed various Ant task bugs.
• Updated documentation and examples.

Aug 2003

Version 1.7

• Fixed various Ant task bugs.
• Fixed ClassCastException due to explicitly used abstract classes with implicitly used interfaces targeted at JRE1.2 (the default in JDK1.4).
• Fixed -defaultpackage bug for protected classes and class members.
• Fixed ReTrace bug when retracing without line number tables.
• Worked around zip package problems with duplicate out entries and rogue manifest files.
• Added work-around for handling malformed legacy interface class files.
• Updated documentation and examples.

May 2003

Version 1.6

• Added support for Ant.
• Added support for the J2ME Wireless Toolkit.
• Added support for reading and writing directory hierarchies.
• Added option for specifying resource jars and directories.
• Added support for wildcards in class member specifications.
• Improved handling of the -defaultpackage option.
• Improved stack trace parsing in ReTrace tool.
• Fixed processing of libraries containing public as well as non-public extensions of non-public classes.
• Fixed examples for processing libraries, midlets, and serializable code.
• Updated documentation and examples.

Jan 2003

Version 1.5

• Fixed processing of retrofitted library interfaces.
• Fixed processing of .class constructs in internal classes targeted at JRE1.2 (the default in JDK1.4).
• Fixed -dump option when -outjar option is not present.
• Updated documentation and examples.

Nov 2002

Version 1.4

• Now copying resource files over from the input jars to the output jar.
• Added option to obfuscate using lower-case class names only.
• Added better option for obfuscating native methods.
• Added option not to ignore non-public library classes.
• Added automatic .class detection for classes compiled with Jikes.
• Updated documentation and examples.

Sep 2002

Version 1.3

• Added support for wildcards in class names.
• Added tool to de-obfuscate stack traces.
• Added options to print processing information to files.
• Added option to rename source file attributes.
• Fixed processing of implicitly used interfaces targeted at JRE1.2 (the default in JDK1.4)
• Fixed processing of configurations with negated access modifiers.
• Fixed duplicate class entry bug.
• Updated documentation and examples.

Aug 2002

Version 1.2

• Improved speed.
• Fixed processing of classes targeted at JRE1.2 (the default in JDK1.4) with references to their own subclasses.
• Fixed processing of static initializers in J2ME MIDP applications.
• Fixed processing of retrofitted interfaces (again).
• Added more flexible handling of white space in configuration.
• Updated documentation.

Jul 2002

Version 1.1

• Added automatic detection of Class.forName("MyClass"), MyClass.class, and (MyClass)Class.forName(variable).newInstance() constructs. This greatly simplifies configuration.
• Added options to keep class names and class member names without affecting any shrinking. They are mostly useful for native methods and serializable classes.
• Fixed processing of retrofitted interfaces.
• Added handling of missing/invalid manifest file in input jar.
• Updated documentation and examples.

Jun 2002

Version 1.0

• First public release, based on class parsing code from Mark Welsh's RetroGuard.