The following suggestions can improve the performance of your animations and make creating animations easier:

Show and hide layers instead of changing the source file for multiple image animations Switching the source file of an image can slow down the animation because the new image must be downloaded. No noticeable pauses or missing images if all images are downloaded at once in hidden layers before the animation runs.

Extend animation bars to create smoother motion If animation looks choppy and images jump between positions, drag the end frame of the layer's animation bar to extend the motion over more frames. Making the animation bar longer creates more data points between the start and end point of the movement and also makes the object move slower. Try increasing the number of frames per second (fps) to improve speed, but be aware that most browsers running on average systems cannot animate much faster than 15 fps. Test on different systems with different browsers to find the best settings.

Don't animate large bitmaps Improve animation speed by not moving large images. Instead, create composites and move small parts of the image. For example, show a car moving by animating only the wheels.

Create simple animations Do not create animations that demand more than current browsers can provide. Browsers always play every frame in a timeline animation, even when system or internet performance decreases. Timelines rely on Dynamic HTML to render animation.

Define keyframes without using the Add Keyframe command. Use this shortcut when creating keyframes: Deselect the animation bars in the timeline, click in a frame to move the playback head, and then edit a timeline object in the Document window.