Before you can optimize the speed of your web pages you must determine how fast they load in their current state. The means by which you do so depends on the way in which your website is deployed. If your site is not yet hosted on a server, you are limited to using offline tools. By their very nature, these tools tend to provide rather rough estimates of download speed, but they are better than nothing.
You can gain a quick estimate of how long a page will take to load by looking at its total size:
In DreamWeaver: switch to Design Mode for the page and look in the bottom right hand corner of the window. DreamWeaver will provide the total size of the page and an estimated download time (over DSL, by default: this can be changed in the application’s Preferences panel). Again, you are looking for a page size under 100K, and a load time of less than five seconds; ideally, less than two seconds.
Under those conditions, creating an accurate estimate means falling back to adding up the file size of the visible content yourself. An easy way to do this in Firefox is to hit CMD/CTRL + I for information about the page: on the screen that appears, the General “size” refers to the file size of the code and text of the page, whereas the elements listed under “Media” are the size of the images and other content.