- MeasureIt "Users can calculate the measurement specifications of tables, paragraphs on internet."
- ColorZilla "Advanced Eyedropper, Color Picker, Palette Viewer and other colorful goodies."
- ScreenGrab "Save or copy the current page, viewport or selection in a png file."
- Load Time Analyzer "Measure and graph how long web pages take to load."
The power of Firefox is in its library of add-ons. There are at least five extensions that a web developer can not live with out.