Flash player compatibility issues

As we all know, Flash 8 has many improvements regarding graphics – font rendering, gradients, line caps, joins and so on.

One thing easily overlooked is compatibility to older Flash players.

Previously, content created in, say, Flash MX2004 and exported for Flash player 7 was visible in Flash player 6 or 5 or even older. The commands the player didn’t understand were silently ignored, but the graphics were visible.

I was expecting this to remain true for Flash 8. If I draw a rectangle with Mitter joins and a drop shadow effect in Flash 8 and I export it as Flash8, Flash player 7 should display the rectangle with the old (rounded) joins and without the drop shadow. Well, I was wrong.

I made a few tests and this is my conclusion:

If you take a file created in Flash MX2004, open it in Flash 8 IDE, export it for Flash8 and view it with Flash Player 7, the content is visible. If you add anything in Flash 8 IDE, even a simple shape with no extra features, nothing is visible anymore.

Why is this important? It’s because at the time of writing, Flash 8 is just a few months old. Its penetration is not officially reported, but I’d say it’s 50%-60% and Google Analytics seems to agree.

My suggestion would be to export to Flash7 if you’re not using any of the new Flash 8 features or, if you do, to have two versions, one for Flash8 and one for Flash7 and use a detection script to redirect the user to the Flash7 version if needed.