by Tom Dahm,
Chief Operations Officer,
If you've looked through your server log files lately, you've probably seen repeated 404 errors for something called "favicon.ico." You never put any file like that on your site, so why does everyone keep asking for it?
Favicon.ico is a special graphic file used by Internet Explorer version 5. IE 5 uses this icon file to display your site's logo in the browser's address bar, like this:
If a user sets a bookmark to your site, your icon will also appear in the bookmark list, like this:
This is a nice effect that can help your site stand out in a long list of bookmarks.
Every time IE 5 visits a Web site, it first asks the server for a copy of the site's favicon.ico file. If there's no such file, the server writes a "404 - not found" message to its log files. Though this sounds bad, it's not really a problem. The absence of a favicon.ico file just means that your site will be displayed with the standard IE page icon on the address bar. The user won't see any sort of error message.
Your icon needs to be 16 pixels wide by 16 pixels high, and it needs to be in the special .ICO file format. That means you'll need to create it using a special icon-builder program, like Cursor Maker or IconForge. Or, if you prefer an online version, visit www.favicon.com, which includes a java applet for building icon files.
To install the file on your site, upload it to your domain root. That is to say, you place it in the same directory as your site's home page.
If you really like this effect, you can create multiple favicon files for different directories in your site. To do this, put a separate favicon.ico file in each directory on the site.
Is this just a gee-whiz effect? Maybe, but it can help your site stand out on your visitor's list of bookmarks, and that's a plus. Or at least it will until everyone else starts using a favicon file. In any case, putting an icon file in your domain root will keep you from getting all those annoying error messages in your server logs.