Spacing.js

A JavaScript utility for measuring the spacing between elements on webpage

How to use

1 Include
<script src="https://unpkg.com/spacingjs" defer></script>
in your HTML page.
2 Move your cursor to an element and press Alt on Windows, or Option on a Mac.
3 Move your cursor to another element, the measurement results will be there.

By the way, you can press Alt / Option now.