Fonts render better at larger sizes (i.e. with less subpixel antialiasing issues). Also, until recently most browsers didn't support subpixel typographic adjus

Fonts render better at larger sizes (i.e. with less subpixel antialiasing issues). Also, until recently most browsers didn't support subpixel typographic adjustments (for instance, "letter-spacing: 0.4px"), and you could only adjust this stuff reliably if your font-size was higher than 20px. That said, 16px is the default base font size on most user agents, and it seems adequate for reading on many devices. However, I tested 16px in Luis's site and it was not quite satisfactory. 19px seems to be the sweet spot in this case. Ultimately, no font-size is perfect for everyone. Be thankful that your browser zoom works ;) Even on a desktop, sometimes at night, with f.lux on, I have to zoom HN to read it comfortably (thankfully Safari has tap to zoom in an area).