De MonsterDebugger is an open source debugger for Adobe Flash, Flex and AIR. De MonsterDebugger is made in Flex and AIR by design studio De Monsters.

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Frequently Asked Questions we get are listed below. If you still have a question after reading this faq and after checking the help that is included in De MonsterDebugger, you can reach us at:

Q: What is De MonsterDebugger?
A: A lightweight open source debugger for Adobe Flash, Flex and AIR projects. Made and maintained by design studio De Monsters.

Q: Why is De MonsterDebugger open source?
A: We believe that by sharing useful tools to the Flash, Flex, AIR community, we can do our part in making the world a better place for designers and developers. Cheesy but true.

Q: Can I use De MonsterDebugger with ActionScript1 or 2 projects?
A: No, the client class of De MonsterDebugger is written in ActionScript3.

Q: What does De MonsterDebugger add to the already existing internal debugger in Flex Builder?
A: The internal Flex Debugger is great, but there are some drawbacks that are not present with De MonsterDebugger.

  • You can't use it if you develop your application or website with the Flash IDE
  • You can't use it on live sites without installing the Flash Debug Player
  • You can't customize the internal debugger to suit your needs.
  • You can't use it to debug installed live running AIR applications (only those that are started from the Flex builder IDE can be debugged using the internal debugger)

Of course there also some features in the internal Flex debugger that we don't support, like memory profiling or breakpoints. But you can use both debuggers during development if it suits your need.

Q: How can I modify De MonsterDebugger?
A: Start by downloading the source files from Google Code: You will need a copy of Flex Builder 3 with the latest SDK (version 3.2.0) to edit and compile the code.

Q: How can I contribute my code to De MonsterDebugger?
A: Get in touch with us by emailing us at . We are always looking for developers or designers who can contribute.

Q: I have a neat idea or found an annoying bug, how can I report this?
A: Just click on the feedback tab on the left side of your screen and tell us your thoughts.

Q: I have included the client class, but nothing shows up in the debugger window?
A: Try to run your application directly from the Flash IDE or on a server (live or localhost).

Q: My application stalls when I use the trace function, what should I do?
A: The object you are tracing might be too large to parse. You could adjust the depth of the trace. Example: "MonsterDebugger.trace(this, myLargeObject, 0x000000, false, #)". Replace # by any number to change the level. Default trace level is 4. You can find more information about advanced traces in the help section in De MonsterDebugger.

Q: Will there be a MonsterDebugger V3.0?
A: We hope so! We are working with De MonsterDebugger on a daily basis. We will continue to update this version if we encounter bugs or come up with new features.

Q: What happened to the previous MonsterDebugger?
A: The previous version is still available in the downloads section but we recommend using the latest version due to improved performance, features and error handling issues.

Q: Are you guys in any way affiliated with Adobe?
A: No, we just use their products on a daily basis and try to make our own work a little bit easier.

Q: Can I use De MonsterDebugger on my Mac, PC or Unix computer?
A: Yes! Although we have only tested De MonsterDebugger on Mac OS X and Windows XP. Since it is made with Adobe AIR it should work fine on Unix, Vista, etc.

Q: What license did you choose for De MonsterDebugger?
A: De MonsterDebugger is released under the GNU General Public License.

Q: Can I hire De Monsters?
A: Sure, just contact us at or check out

Q: Can I use De MonsterDebugger with framescripts?
A: No, framescripts are for douchebags.


Download MonsterDebugger version 2.5.1 (examples included)

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