Interactive type testers that let visitors set their own text at various sizes, weights, and styles are essential for evaluation. Specimen pages showing the typeface in realistic use cases -- editorial layouts, UI mockups, signage -- help designers envision how the font will perform in their projects.
Subsetting fonts to include only the characters needed for preview, lazy-loading heavier weights and styles on interaction, and using variable font files that contain an entire family in a single download all help manage page weight. Progressive loading ensures the page is usable before every style has arrived.