Font Brief is a discovery tool that narrows down typefaces using sliders - expressive vs. neutral, elegant vs. rugged, serious vs. friendly - instead of an alphabetical list.
The slider approach is a genuinely different way to search than most font sites, useful when you know the mood you want but not the name of a typeface that matches it.
Suited to branding or editorial work where you're trying to describe a feeling rather than search for a category like 'sans-serif.'
Access is free but gated behind a newsletter signup; it doesn't host fonts itself, so the license for whatever you find still depends on that font's own source.