1.     Webpages that use JavaScript are written with the script at the top of the document.  The content cannot be seen until the JavaScript has loaded in. If the JavaScript is placed at the bottom of the document the page content will load first which will cut out some of the load time. The page will still be loading when it is visible within the browser but the user will be oblivious to this.

2.     Loading in external documents such as style sheets or JavaScript files can also add to a page’s load time. If you include the external files within the main html file it makes the code less readable but it also lessens the load time. When the website is complete and the code readability is less of an issue you can paste external files into the main html file.

3.     There are several different image formats, the most common are Portable Network Graphics (png), Joint Photographic Experts Group (JPEG) and Graphics Interchange Format (gif). Different formats give a different quality of image and more notably vary the it’s file size. A gif type image is the smallest format so if your graphics only contain a few colours then this would be the primary choice. JPEGs can vary in quality and consequently in file size also. You should target the smallest size that doesn’t reduce the quality of the image. PNGs have the greatest file size of the three and should only be used for high quality images with transparent backgrounds. Bitmaps (bmp) are another common image file type but take up a lot of memory. These should be avoided altogether for web use to ensure speedy page load times.

4.     The use of images, in particular animated gifs, increase page load time and should be used in moderation. Animated gifs are made up of more than one image and therefore have a greater file size. The lower the file size of the externally loaded image, the quicker the page will load. Also the amount of files being loaded in externally plays a significant role in page load time.

5.     Flash animations or swf files are used more frequently these days than animated gifs. Swfs are a considerably greater size than that of animated gifs. They should only be used on a page where absolutely necessary. If your animation is brief and doesn’t require any user involvement it might be worth considering using an animated gif instead. Nevertheless it should also be noted that if your animation uses audio a gif won’t be appropriate. The use of swfs will also require extra code to check if the user has a flash player installed. Further code equates to a greater file size and is therefore another reason to only use swfs where necessary.

6.     It is advisable to combine separate images where you can to decrease page load time. Two separate graphics will have a greater overall file size than one. Also with only one graphic the site needs to make less http requests, which is another determining factor of page load time.