- Keep it simple and stupid. Instead of using fancy
bullets (such as the ubiquitous colored balls) or creative horizontal
rules, stick with the built-in widgets. It may save a few seconds of
loading time and will look good on every browser.
- Don't insist on putting thumbnail pictures of the sites you are
linking to. This used to be the rage, but it took forever to
load then, and it still takes
forever to load (Caution: many inlined images).
It looks totally unprofessional, especially when the pictures or icons are
not the same size. And the "broken or missing picture" icons that appears
if your images are not available looks bad and distracts from your page.
- Don't be an image parasite. An image parasite is someone
who inlines pictures from someone else's server rather than serving them
himself or herself. This is a big no-no, unless the owner has given
explicit permission for you to do so (for example, Netscape asks authors to
load backgrounds from their server rather than downloading copies of them).
Being a parasite is a Bad Idea (tm) because it burdens the host's server
without the host getting any credit (or compensation).
Don't think that you can get away with leeching, either. With the advent of
referrer logs, it's possible for a Web author to determine which
remote Web page is causing so many hits on his or her server. Armed with this
information, you're likely to get a nasty piece of e-mail at the least.
- Use the WIDTH and HEIGHT attributes in all <IMG>
tags. One of the strongest features of advanced browsers is the
ability to lay out and display text before images begin to load. That way,
users can read text or follow links without having to wait for the
document to load completely. If you do not put WIDTH and HEIGHT
information for your images, then browsers must wait until they
receive all the image information to figure out how to properly display
Rather than having to go through every picture on all of your pages and figure
out the dimensions, try using a neat
WWWis, that will automatically determine the sizes of all
referenced images in an HTML document then alter the tags accordingly.
- Avoid inlining JPEG images. First, only the latest
generation of graphical browsers supports inlined JPEGs, which means
older browsers will not be able to see those images. Second, most browsers
are used with 16- or 256-color displays, meaning the browser will dither
your nice 24-bit graphics down to GIF-quality 8-bit depth. Third, you
can't interlace JPEGs (see next tip).
JPEGs are good for reducing the size of graphics
files for faster transport, but your inline graphics shouldn't be very
large to begin with (try to keep all inlines under 30 KB). Save
JPEG images for large, high quality, linked pictures or for
small, low resolution <LOWSRC> images (see
Creating High-Impact Documents for details on using JPEGS in this
- Interlace, interlace, interlace. If you use GIF
images, you should interlace them. Interlacing allows the browser to
display the image as it downloads. This gives the reader the
impression that the picture is loading faster than it actually is. It also
creates a cool visual effect: a fuzzy picture that "focuses" to a sharper
and sharper image. For a demonstration, see
Creating High-Impact Documents.
There are several tools that will create interlaced GIFs from your boring
and slow GIFs.
GIFConverter (Macintosh) and
L View Pro
(16- and 32-bit MS-Windows) are easy-to-use utilities that also provide
basic image editing and conversion functions. On Unix platforms, I
- Give download information on linked pictures. For
example, instead of:
Add some useful information that will all the user to decide whether she or
he can "afford" to download it:
- Here's the Home Page Construction Set's ultra-lame
masthead graphic [16 KB, 320x200 GIF].
Without the extra information, the reader has no clue whether his or her
browser can even display it (for example, Netscape cannot display TIFF files,
while WebExplorer can) or how long it will take to download (1.3 MB takes
significantly longer than 20 KB!).
- If you have an image archive, include thumbnails of all
downloadable graphics. Few things are more frustrating than
having to download every file in order to find the image you are
looking for. It's a complete waste of time, network bandwidth, and money
for readers to have to download the full sized files to browse your
collection. Thumbnails will save time, and will improve the appearance
of your pages if done correctly.
For example, if I had a directory full of images, I might create a download
page with entries similar to this one:
The Home Page Construction Set's ultra-lame masthead
graphic. Eric's simplistic interpretation of HTML source transformed
into a rendered Web page.
[16 KB, 320x200 GIF]
Keep your thumbnails small (roughly 2-3 KB) and about the same size (don't
forget to include WIDTH and HEIGHT in your <IMG> tags!).
Quality doesn't matter as long as you can identify the images. You should
also limit the number of thumbnails per page to around 10 or the next Ice
Age could be here before the page is finished loading.
- Quantize the color maps in your images down to a standard
colormap. This is an advanced tip; your ability to do this
will depend on your access to color editing software and your desire to
tinker with the dozens of colors that make up your images. If you've
ever loaded a picture and the colors of your windows change to a unique
combination of neon colors in the process or if an image displays completely
different in a Web browser than in a graphics program, you've seen
the effects of a colormap conflict.
A conflict occurs when the number of colors requested by
all screen elements (images, windows, desktop, etc.)
exceeds the number of colors that can be displayed at once by your system.
For most systems, this is 256 simultaneous colors. To resolve the conflict,
the browser will either
- honor the colors requested by the image you want to display, causing
the "neon" effect--the browser arbitrarily assigns existing colors to
other elements in the screen, freeing up the colors needed to display the
- dither the image. Dithering reduces the number of colors in an image
by matching them to the existing colormap. This operation usually results
in a displayed image with slightly different colors than the original one
and/or a loss of image sharpness and quality.
To avoid a conflict, you should try to have your images share a common
colormap. This colormap should ideally be around 200 colors so as to
allow enough free colors for the browser and system demands. Advanced
image correction and editing software will allow you to change all of your
images to a common color map. Even if you don't create a common colormap,
try to reduce the number of colors in your images to avoid conflicts, either
by directing your image software to save with a reduced colorset or by
manually editing the colormap (for example, similar "white" colors should
be replaced with a solid white).
I recommend Adobe
Photoshop (Windows, Macintosh),
L View Pro
(16- and 32-bit MS-Windows) to edit your image colormaps.