Thanks for posting this! It's an absolute godsend for creating small vector icons.

As an example, I was looking at various popular sites for how they implement the "hamburger menu" icon, and it turns out that YouTube has a really compact one:

    M21,6H3V5h18V6z M21,11H3v1h18V11z M21,17H3v1h18V17z

When I tried implementing my own in something like Inkscape, it always uses floats for coordinates, no matter how hard I tried to coax it into a fixed grid or using integer values. With that problem alone, you will never be able to get a compact path.

This editor is perfect for doing this.

jhgb

Smart quantization of SVG paths sounds like a neat problem. Is there no existing tool for it already? Along the lines of pngcrush or similar.

This may be too-stupid-to-work but what immediately comes to my mind is normalizing all coordinates into an [0,1]x[0,1] interval and then finding an optimal N so that the maximum rounding error for quantizing all coordinates to the nearest K/N (where K is a non-negative integer up to N) is minimal (for some definition of "optimal", since you have two criteria now - resulting path string length AND maximum rounding error achieved for a given N). Then all your coordinate components should be integers in the range of [0,N].

pilaf

There's SVGO (https://github.com/svg/svgo).