Verified answer

swf is

vector based

needs a bespoke player

supports more colours

allows for interaction

gif's

bitmapped based

supported by html

has restricted colours

you can only play and watch

can't have sound

cool_clearwater summarized most of them beautifully. I just want to add one thing: while gifs take up a lot of disk space for what you get, in actual memory swfs are a HOG which WILL crash a certain percentage of users browsers (depends on the swf what the percentage is) and will usually run slowly and/or intermittently. You can do more with it and embed it in web pages but generally web pages work better when designed by people who understand that less is more.

Swf;

Needs a flash player

Can be slow for the target

Expensive software to make

Requires a lot of knowledge to create good ones

lots of colours

easy to animate

GIF;

Frame by frame animation

long time to make

can run on and web page/computer

Expensive software not needed

Restricted colours

Pictures GIF can be animated too although you can make movies on Flash (SWF) only.

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