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JPEXS Free Flash Decompiler

Open Source Flash SWF decompiler and editor. Extract resources, convert SWF to FLA, edit ActionScript, replace images, sounds, texts and fonts. Various output formats available. Works with Java on Windows, Linux and macOS.

Application description and features

For information about using the software, list of features, etc., visit FFDec Wiki. website

In the past (before 2018), we were using domain as homepage and GitHub for the source code, We've now moved all information to GitHub.

Download application

For downloading the app, see latest release. Older versions and nightly builds are availabe at the releases section

How to install

See installation section of the wiki

Source code

How to get the source

You can make a local copy of the sources with the following command:

git clone

This assumes you have git installed on your system.


Git source control manager supports multiple code branches. We use two main branches.

  • master - for released "stable" versions
  • dev - for newest changes from developers - "nightly" version is released from this branch

You can switch to dev branch with following git command:

git checkout dev

GIT recommended

It is recommended to have GIT commandline executables installed. Building script uses GIT to include revision number in to the binary. (For Windows, you must enable Git in windows command line during installation.)

Netbeans project

Source code contains Netbeans Project so you can open it in Netbeans IDE. Then you can use standard actions like Run, Build, Debug, Clean and Build in the IDE. Other specific tasks can be executed via menu on build.xml (see Ant part)


If you do not have Netbeans, you can build source code also with Apache Ant. After installing Ant it is good to put it into your PATH variable. Open up commandline and navigate to sources directory. To run application, execute task "run" by entering this command:

ant run

To only build, execute build task:

ant build

For creating EXE, Installer and ZIP version, there exist Ant tasks "exe","installer","release". These tasks require additional software installed:

  • launch4j (3.5 or newer) - creates windows executable
  • NSIS (Nullsoft Scriptable Install System) (3.0b3 or newer) - creates installer

You must configure installation path of these tools in file, which could look like this for windows:

nsis.path = c:\\program files (x86)\\NSIS
launch4j.path = c:\\program files (x86)\\launch4j

Building libraries

There are few libraries which need to be built too. These libraries are placed in "libsrc" directory.

  • FFDec_lib - core of decompilation, SWF parsing, exporting This library is built automatically with main project, but can be build also separately with its own Ant script.
  • jpacker - used for compression of JavaScript Canvas scripts (Netbeans/Ant project)
  • jpproxy - proxy part of FFDec (Netbeans/Ant project)
  • jsyntaxpane - code editor (Netbeans/Apache Maven project)
  • LZMA - used for SWF compression (Netbeans/Ant project)
  • nellymoser - used for Nelly Moser sounds decoding (Netbeans/Ant project)
  • Swf2Exe - Stub for "Save to EXE" feature (Delphi 7 Project)
  • ttf - used for TTF font export (Netbeans/Ant project)
  • gnujpdf - used for PDF export (Netbeans/Ant project)

Change log

All notable changes are listed in the file


Nightly builds

When a commit is pushed/merged into dev branch, a new prerelease version is created automatically by the Travis CI. These prerelease versions are called nightly builds. On releasing a new nightly build, the previous nightly build is removed.

Stable versions

A new stable version is created automatically by the Travis CI when marking a revision in master branch with a tag in format versionx.y.z.


Please read for details on our code of conduct, and the process for submitting pull requests to us.


Versions are in format x.y.z, for example 9.1.2. For the versions available, see the tags on this repository.

Nightly builds have additional suffix _nightlyN where N is number which increments with every (automatic) nightly releleas and does not depend on the x.y.z numbers. (This means nightly number is NOT reseted to 0 when releasing stable) Older nightly builds are NOT available through git tags.


The decompiler was originally written by Jindra Petřík also known as JPEXS. The application was made in Czech Republic.


  • JPEXS - leader, development of the decompiler, website main admin, github account admin, organization
  • honfika - development of the decompiler
  • Paolo Cancedda - former developer
  • ...other pushers on GitHub or Google Code


  • Jaume Badiella Aguilera - catalan translation
  • Capasha - swedish translation
  • 王晨旭 (Chenxu Wang) - chinese translation
  • focus - russian translation
  • honfika - hungarian translation
  • kalip - italian translation
  • Krock - german translation
  • Laurent LOUVET - french translation
  • MaGiC - portugese translation
  • martinkoza - polish translation
  • Osman ÖZ - turkish translation
  • pepka - ukrainian and dutch translation
  • poxyran - spanish translation
  • realmaster42 - portugese-brasil translation
  • Rtsjx - chinese translation
  • koiru - japanese translation


You can use our Issue tracker to report bugs, but our support is VERY limited.

See Frequently Asked Questions (FAQ) in wiki before you try to contact me.

Email contact

Emergency contact to JPEXS developer is But we prefer Issue tracker contact.

Licenses + Acknowledgments


FFDec Application is licensed under the GNU GPL v3 (GPL-3.0-or-later) licence, see the license.txt. It uses modified code of these libraries:

And links also these libraries:

Application uses also some icons of the Silk icons pack, Silk companion 1 and FatCow icons pack.


FFDec Library is licensed under GNU LGPL v3 (LGPL-3.0-or-later), see license.txt for details. It uses modified code of these libraries:

  • sfntly (WOFF font export) - Apache License 2.0
  • JLayer (Decoding MP3) - LGPL
  • UAB "DKD" NellyMoser ASAO codec (Decoding Nelly Moser sound format) - LGPL
  • Animated GIF Writer (Frames to GIF export) - Creative Commons Attribution 3.0 Unported
  • Animated GIF Encoder (Frames to GIF export)

And also links to these libraries: