PixelSnap alternatives

A tool for designers to measure screen dimensions This extension measures the dimensions from your mouse pointer up/down and left/right until it hits a border. So if you want to measure distances between elements on a website this is perfect. It doesn't really work with images because there the colors change a lot pixel to pixel.

UXsniff detects and reports abnormal user behavior, such as manic repeated clicks or scrolls on your website, automatically. Unleash your website's full potential today. Use UXsniff to improve what's working, fix what isn't and test new ideas.

MeasureMate the ultimate tool for measuring distances between elements on webpages. It lets you just select the element and then check all the distances to any other element. You can select the whole element or only the content box.

xScope is a powerful set of tools for Mac OS X that are ideal for measuring, aligning and inspecting on-screen graphics and layouts.