Flash formats and objects overview

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This articles lists a few file formats and objects you can have on the stage or in the library and explains some of the terminology. It is part of the Flash series.

It's purpose is to help you identify objects you are working with as a Flash designer. We don't use the term "object" here in the sense of an ActionScript object !

Note: This text is a rough draft. Some things may be wrong or missing.

Flash related file formats and extensions

Copyright notice: The table below has been copied more or less as it from Wikipedia's Macromedia Flash article on July 12, 2007. Its contents are available under the GNU Free Documentation License.

Ext. Explanation
.swf .swf files are completed, compiled and published files that cannot be edited with Adobe Flash. However, many '.swf decompilers' do exist. Attempting to import .swf files using Flash allows it to retrieve some assets from the .swf, but not all.
.fla .fla files contain source material for the Flash application. Flash authoring software can edit FLA files and compile them into .swf files.
.as .as files contain ActionScript source code in simple source files. FLA files can also contain Actionscript code directly, but separate external .as files often emerge for structural reasons, or to expose the code to versioning applications. They sometimes use the extension .actionscript
.swd .swd files are temporary debugging files used during Flash development. Once finished developing a Flash project these files are not needed and can be removed.
.asc .asc files contain Server-Side ActionScript, which is used to develop efficient and flexible client-server Macromedia Flash Communication Server MX applications.
.flv .flv files are Flash video files, as created by Adobe Flash, ffmpeg, Sorenson Squeeze, or On2 Flix. It's container format that uses (mostly) h.263 for video and MP3 for audio.
.swc .swc files are used for distributing components; they contain a compiled clip, the component's ActionScript class file, and other files that describe the component.
.jsfl .jsfl files are used to add functionality in the Flash Authoring environment; they contain Javascript code and access the Flash Javascript API.
.swt .swt files are 'templatized' forms of .swf files, used by Macromedia Generator.
.flp .flp files are XML files used to reference all the document files contained in a Flash Project. Flash Projects allow the user to group multiple, related files together to assist in Flash project organization, compilation and build.
.spl .spl files are FutureSplash documents.
.aso .aso files are cache files used during Flash development, containing compiled ActionScript byte code. An ASO file is recreated when a change in its corresponding class files is detected. Occasionally the Flash IDE does not recognize that a recompile is necessary, and these cache files must be deleted manually. They are located in %USERPROFILE%\Local Settings\Application Data\Macromedia\Flash8\en\Configuration\Classes\aso on Win32 / Flash8.
.avi AVI file is a video file, standing for Audio Video Interleave. Flash includes several compression codecs, including some from Radius.
.gif A GIF image; either a single static frame or multi-frame animation.
.png A PortableNetworkGraphic image.

On the stage

On the stage you can have various kinds of graphics objects, i.e. objects that you can move, copy, delete, transform, stack, align, and group.

See also the Flash drawing tutorial, Flash object transform tutorial and Flash arranging objects tutorial for more details.


Shapes are the most primitive objects. When you draw shapes that overlap each other in the same layer, the topmost shape cuts away the part of the shape according to your drawing controls. When you draw a graphic like a rectangle in merge mode with both stroke (the outline) and a fill (paint), they become separate shapes and can be moved independently.

You can transform a shape into graphic object with menu Modify->Combine objects union

Tip: As a general rule, avoid shapes (unless you work like a painter or a drawing artist). In other words, put the controls of the Tools panel in object mode: object button pressed

Graphic objects

When you draw in object mode, then you will produce graphic objects. You can transform a graphic object into a shape (right-click->break Apart).

Composite objects

When select several objects you have a composite object. When you group them together too.

There exist different variants:

  • Group: A group of graphics object and shapes
  • Mixed: A group of graphics and e.g. a component instance.

Tip: Make sure that you don't work on a composite object when you believe that you just edit a simple object. E.g. watch out what you have selected before you turn it into a symbol ...


Instances are made from objects that you have in your library. You only can apply certain transformations to these (without changing the library objects). E.g. you can

  • Change its tint or brightness and alpha (transparency)
  • You can scale, rotate and skew it with a transform tool. But can not apply envelope transforms
  • you can move them of course.

You can attach behaviors to instance object in ActionScript 2. In ActionScript 3 you can also do this, but only via the timeline.

Some instances let you edit parameters, i.e. compiled clips

Special objects

Modifying lines and shapes can alter other lines and shapes on the same layer. See Flash motion tweening tutorial for example.

In your library

Graphic symbols

Graphic symbols are named graphic objects. You can transform a drawing or shape into a graphic symbol with the right-click menu. Actually, as soon as you are happy with a creation you should do this.

Movie symbols

Movie symbols are Flash animations that you can edit by double-clicking. You can use them as components for more sophisticated animations.

Button symbols

Button symbols are special movies that implement the graphics or button touching, pressing, releasing, etc.


Bitmaps Are imported bitmaps of various formats, e.g. *.jpg, *.gif, *.png


Represent motion tweens. I never use these. If you have these in your library it means either:

  • You are an advanced Flash designer
  • Something went wrong when you made a motion animation (e.g. you animated more than a single object or an editable object).

Movie clips

Movie clips are simply imported Flash files *.swf. You can drag them on the stage and for example use them in a motion animation.

Compiled clips

Compiled clips are ActionScript objects exported/imported trough the *.swc format. If you drag an instance to the scene you then can edit its particular parameters through the properties or the component inspector panels.

Flash videos

These are Flash video containers in *.flv format. When you drag these to the stage, they will integrate to the timeline. E.g. a short movie may extend over several hundred frames. Most often you'd rather use the FLV playback component to play such videos. See the Flash video component tutorial.