MeasureIt 0.4.8 (Firefox 4 compatible) is a great app for web designers as they can measure anything in their browser frame with the ruler. MeasureIt for Firefox adds a toolbar button with which you can draw a ruler on screen and measure height or width of any component that is in your browser frame.
How to run MeasureIt in Firefox 4
I installed MeasureIt on Firefox 4, but couldn’t locate the button. It installed correctly but MeasureIt disappeared after it installed. Some experimentation lead me to a solution that I thought would be worth sharing for those who have MeasureIt missing issues.
Step 1: Install MeasureIt-0.4.8-fx.xpi and restart your browser
Step 2: Enable the Firefox 4 add-on bar (if you want MeasureIt button to be shown on Status bar / add-on bar)
Step 3: Right click on add-on bar and click “Customize…”
Step 4: Locate the MeasureIt button and drag it to the location where you want it to be shown.

Step 5: Click on MeasureIt button and start measuring.
Oh and in case you didn’t know, you can run Firefox 4 and Firefox 3 simultaneously and install separate extensions for both.









