Is it better to use Javascript or Flash to create slideshows for your web site? Well since this is the Javascript site and not the Flash site you can probably guess what my answer is.
You are of course entitled to form your own opinion as to which is the better way to create a slideshow but to be able to do that you need to be in possession information as to the advantages and disadvantages of each. I am going to present the case for why Javascript is a better choice for creating slideshows than Flash. I will leave it to the Flash supporters to present their case.
One comment that you often hear about Javascript is that a certain percentage of web users have Javascript disabled or use browsers that don't support Javascript - I have seen figures of 10% mentioned. What may not be so obvious is that to run Flash on a web page your visitor is required to have a Flash plugin installed into their browser. I think that it is fairly safe to say that any browser that doesn't support Javascript doesn't support plugins either. I also think that anyone who has disabled Javascript in their browser will almost certainly have disabled Flash as well. There will also be some people who allow Javascripts to run (since Javascripts are relatively safe and don't require a plugin but who either have plugins disabled or don't have the Flash plugin installed and who are not interested in downloading and installing that plugin. The percentage of visitors without Flash will therefore be somewhat higher than the percentage of visitors without Javascript. So more people will see a Javascript slideshow than will see a Flash slideshow.
Apart from the inconvenience of having to download and install a plugin in order to view Flash, one major problem that I have seen with Flash is that many people don't know how to code it properly. They end up with a Flash file that is perhaps 10 or more times the size that it needs to be to produce the required effect which makes the web page e-x-t-r-e-m-e-l-y s--l--o--w. Sure people can miscode Javascript as well but with a Javascript slideshow the script and the images are all separate files and that makes it easier for the person who created the slideshow to improve the performance by optimizing the individual files.
In addition a Javascript slideshow does not need to download all of the images before it can start displaying them while a Flash slideshow is typically all in one file which must download completely before the slideshow can start. This means that a Javascript slideshow will appear to run faster even if its combined file size is as large as the Flash file.
A javascript slideshow is easier to modify after it has been created. All that is needed to add an additional slide into the middle of an existing slideshow is a one line update to add a reference to the new image in the array that references all of the images.
For those with Javascript and Flash disabled or not supported the Javascript slideshow still has advantages. Sure such visitors will not see the slideshow as it is meant to be seen but you can easily set uo web pages that will allow such visitors to view all of the separate images in the Javascript slideshow. To be able to do the same with a Flash slideshow means creating a set of static images that duplicate the ones in the Flash presentation.
May be your not yet convinced. Well there are still more benefits to using Javascript rather than Flash. With a Flash slideshow your visitor sees what the Flash shows them. With Javascript you have easy ways to add additional controls at any time that will allow your visitors to interrupt the presentation, jump about within it, or whatever else you think your visitors may like to do. To add extra controls into the Flash means recreating the presentation and uploading the entire file to the server once more.
Javascript slideshows are better than Flash slideshows both for you as the author of the slideshow and for your visitors who view it.
