Optimising Images for the Internet

Are your images sometimes slow to load?

One of the things that many people get confused over is how to optimise an image for the Internet. Images that come straight from a digital camera or from an imaging editing program are often just too big for the Internet. Here are some tips to help - they are not the last word on the subject but they should help a little.

Remember not everyone will have a fast connection and if you site loads slowly you will lose viewers.

Tip 1 - Use the right kind of image for the job

There are really three kinds of images that will work on a web site and they are: jpg (or jpeg), gif or png. Although "png" is a valid format it is best left alone for web graphics because the files are often larger than jpg or gif and not all browsers support them.

Use jpeg for photographs. Any kind of complex image that is made up of a variety of colours and shades are generally better off as a jpg file.

Use gif for drawings. If an image has blocks of colours like a clipart image or some web buttons etc then they are generally better as gif files.

This is not always true but it generally helps to think along these lines.

Tip 2 - Make your picture the right size.

If you have to resize a picture inside a web editing program by grabbing the little "handles" and dragging then you have a problem. Always make sure that your image is the same size as the image that you will display on your web site. For instance if the width on the web page is 120 and the width in your picture editing program is 250 you should resize the image in your picture editing program to 120. Although the image will appear the right size on the web page if you don't it will be twice as big as it needs to be and will take twice as long to download.

Tip 3 - Make your picture the right resolution

This is particularly important if you are using an image from a digital camera. The kind of resolution (often measured in dots per inch or dpi) you need for printing makes a file much too big in file size for the internet. A file only needs to be 72 or 96 dpi to look good on a screen and anything over this is just going to slow down the image from getting to the users screen.

Tip 4 - Reduce your image

There are many picture editing programs these days that will reduce your image to its bear minimum size for the Internet.

There are free ones:
Picasa
www.gimp.org

Inexpensive ones like:
Ulead Photo Impact
Serif Photo Plus

Expensive Professional Packages:
Adobe