Font pairing
Choosing two typefaces that work together: close enough in mood to feel intentional, different enough that nobody mistakes one for the other.
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What it is
Font pairing is picking two (rarely three) typefaces that share enough to feel like one voice and differ enough that you can tell them apart instantly. The working rule: similar mood, different skeleton. Georgia with Verdana works because both were drawn for screens with big x-heights; Playfair with Inter works because the high contrast serif and the neutral sans are obviously not the same creature.
Three shortcuts that almost always land. One, use a superfamily (IBM Plex Serif with IBM Plex Sans, Source Serif with Source Sans): the pairing was designed for you. Two, use one family across the whole page and separate heading from body by weight, size, and tracking instead of by typeface. Three, pair across categories: serif heading with sans body, or the flip, which reads more editorial.
The classic failure is two fonts that are almost the same. Helvetica with Arial, or two humanist sans faces, looks like a rendering bug rather than a decision. The other trap is x-height mismatch: pair faces with wildly different x-heights and you have to nudge one font's size by a few percent so 16px and 16px actually look equal.
Ask AI for it
Pair two Google Fonts for this site. Headings: a high contrast serif (Playfair Display) at weights 600 and 700. Body: a neutral sans (Inter) at 400 and 500. Check that the two x-heights look matched at the same pixel size and adjust body size if not. Use exactly two families, at most four weights total, and separate hierarchy with size, weight, and color rather than adding a third typeface.