# Why do my SWF files contain my source code?

**URL:** <https://forum.kirupa.com/t/why-do-my-swf-files-contain-my-source-code/319321>\
**Category:** flash\
**Created:** [February 16, 2011, 10:22am UTC](https://forum.kirupa.com/t/why-do-my-swf-files-contain-my-source-code/319321 "2011-02-16T10:22:40Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![shedokan](https://avatars.discourse-cdn.com/v4/letter/s/977dab/32.png) [@shedokan](https://forum.kirupa.com/u/shedokan)\
**Post date:** [February 16, 2011, 10:22am UTC](https://forum.kirupa.com/t/why-do-my-swf-files-contain-my-source-code/319321/1 "2011-02-16T10:22:40Z")

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Hi,  
I have been developing AS2 and AS3 games and such and only the last week I found out that my SWF files contain all of my source code with ALL of my variable names.  
And not only that I found out that adding a single space( ) adds 2 bytes to the size of my SWF file.

So I would like to know if any of you know why the SWF files contain the source code with variable names and why adding a single space changes the size of my SWF file.

I thought my source is compiled but just compressing my source code is not called “compiling”.

Thanks.

PS: I know there are tools to obfuscate my source but why do I need them at all?