Yes — Source Serif is free to download from Google Fonts. Read the licence it ships with before you use it in client work.
Source Serif is a serif typeface from Adobe.
Start with Adobe’s other releases — Kepler. They come from the same studio that drew Source Serif, and A1 has 1 website using them.
Source Serif 4 is a serif typeface in the transitional style, designed to complement the Source Sans Pro family. The close companionship of Serif and Sans is achieved by a careful match of letter proportions and typographic color. Source Serif is loosely based on the work of Pierre Simon Fournier, and many idiosyncrasies typical to Fournier’s designs (like the bottom serif on the b or the middle serif on the w) are also found in Source Serif. Without being a pure historical revival, Source Serif takes cues from Fournier and reworks them for a modern age.
A1 features 3 websites using Source Serif, including Rise Plasma, Undone, and Mono. They lean towards Sans-serif, Gradients, and 3D design styles, and they’re most often built with Framer and Webflow.