Font hinting and rendering

Hinting is information in a font that helps its vector outlines line up with the pixel grid at small sizes. Rendering is the larger pipeline that rasterizes those outlines and smooths their edges. The font, size, display density, browser, and platform rasterizer all affect the final pixels, which is why the same file can look different under Windows DirectWrite and macOS Core Text.

Reach for this vocabulary when small UI text looks soft, uneven, or clogged on a target device. Test the real font files at the actual sizes and weights you ship. A family with good screen hinting and sturdy text cuts usually beats a pile of CSS tweaks, especially on lower-density displays: Verdana and Georgia exist because Microsoft commissioned Matthew Carter to draw for the pixel grid, then had Tom Rickner hint them heavily for it.

The gotcha is trying to force identical pixels everywhere. The platforms already disagree by design: Windows ClearType pulls stems onto the grid, and macOS stopped doing subpixel antialiasing in Mojave in 2018, which is why type on a Mac started looking thinner overnight. '-webkit-font-smoothing' is nonstandard and does not replace hinting or control every platform's rasterizer. Avoid making it a global cure. Load real weights instead of synthetic bold, compare at 100 percent zoom, and judge readability rather than demanding screenshot-perfect edges across operating systems.