TechNote (Archived)

How big can a Flash movie be? [Flash CS4 Professional]

NOTE: Adobe Technical Support will not support or assist with issues using elements beyond these limits.

These limits are tested in the Flash and Flash Player development cycles, but if you choose to develop beyond these boundaries we cannot guarantee consistent behavior. You may experience varied issues including graphic artifacts, low memory, slow graphic performance and crashing. If you are experiencing these issues closely examine the requirements of the project and re-architect within these limits.

What is the limit?

Some Flash users are curious about the limits of Flash in the areas of symbols, layers, file size and ActionScript expressions. While these limitations are not documented, every program has logical limits. Many of those limits are difficult to pinpoint, as they may vary from computer to computer, and are often dependent on things such as RAM, CPU, operating system, video card, and browser version. There is an additional factor of chance, as users often use Flash in ways that may have not been intended by the program's designers.

Sometimes an intended behavior is achieved, and other times it fails. A failure may be due to a limit in the program or on the machine being used for playback.

When asking the question, "how big can a Flash movie be?" defer to the obvious. Flash was created to make small, streamable, vector-based files for web delivery. This is the usage addressed by the bulk of the documentation, and it is where Flash performs best. Flash can also be used for nonstandard purposes, such as CD authoring, desktop publishing, stand-alone application building, and other uses. While you can do these things, it's important to ask yourself, "Is this program designed to do what I am attempting? Is there a better program for this use, should this one fail?"

Timeline

16,000 frames: Exceeding this limit causes the movie playback to stop. While this limit is rarely reached by most developers, it is possible. If your movie must have more than this number of frames,try creating multiple movies with fewer than 16,000 frames each and then linking the movies togetherusing a method such as the ActionScript 2 loadMovie() command.
16,000 layers: Flash is not capable of working with more than 16,000 layers in a movie.
16,000 loaded movies: You cannot load more than 16,000 movies into Flash player.
16,000 symbol instances: Flash does not allow more than 16,000 symbol instances in a Flash movie
2880 x 2880 px canvas size: A Flash movie cannot be larger than 2880 px wide or 2880 px tall.

Combining multiple limits in a single Flash file creates greater risk. Flash and Flash Player are optimized for normal circumstances, and testing the extreme limits of Flash can cause memory and other operating system issues.

ActionScript

32 KB: This is the limit in file size for any single ActionScript script such as a class. If you require a larger file, try breaking up your code into smaller parts or delegating responsibilities to other classes.
12 bytes: This is theminimum space in memory taken up by ActionScript variables. This does not include additional space for name or enumeration flags. The actual content (for example, the actual string assigned to a string data type) adds additional bytes.
15 seconds: This is the amount of time a loop will run until a dialog with the message "A script in this movie is causing Flash Player to run slowly" appears, allowing the user to abort the script.
125 components: We recommend that Flash Applications built with Version 2 components be limited to 125 components. This is a suggestion for best performance, not a hard rule.

Because ActionScript is an interpreted language, variables take up quite a bit more space than they would in a compiled language like C++. It is difficult to predict exactly how much space because of the interpreter's various data structures.

The possibilities are endless, but memory is not. Having described the theoretical limits above, it is not recommended that users approach them for practical purposes.