If you're hunting for Sans x
Frisk fanfiction recommendations, I usually dive straight into 'Undertale' communities where fans collect and curate the best stuff. My go-to is Archive of Our Own (AO3) — the tag system there is golden. Search tags like 'Sans/Frisk', 'Sans x Frisk', or 'Frisk/Sans' and then filter by number of kudos, bookmarks, or hits to find the most-loved stories. AO3 lets authors put detailed content warnings and relationship tags, so you can quickly skip things that aren't your vibe and zero in on specific tropes like 'hurt/comfort', 'fluff', 'angst', or different AUs. FanFiction.net still has a bunch of Undertale works, but its tagging and mature-content options are more limited, so I tend to use it only when looking for older classics that never migrated to AO3.
Outside of the big archives, Tumblr and Twitter (X) are full of rec blogs and mini-lists. On Tumblr, tags such as 'sans x frisk', 'sansfrisk', and 'frisk sans' often lead to reblogs with commentary, which I love because you get a personal take with each rec. Wattpad and Quotev host longer, serialized romances and AUs that appeal to readers looking for slower-burn, chapter-by-chapter reads — expect a more YA vibe there. Reddit is great for crowdsourced lists: the 'Undertale' subreddit and smaller fan subcommunities occasionally pin recommendation threads where people note favorites, warnings, and what makes each fic stand out. If you hang out on Discord, look for Undertale fan servers; many have dedicated recommendation channels and real-time rec swaps from people who share your tastes.
A few practical tips I always use: read author notes and the Warnings/Tags section first, especially with shipping like Sans x Frisk where content can range from very wholesome to dark and mature. Use AO3’s filter options to limit by rating (e.g., Teen, Mature, Explicit), completion status, and word count, so you don't accidentally start a 200k WIP when you want a short, complete oneshot. Follow rec lists and bookmarks — when someone curates a themed list (like cozy domestic AUs or time-travel angst), I usually find at least one new favorite. Bookmarking or leaving kudos on AO3 is a small way to support creators whose styles you enjoy, and you’ll also get notified if they update a story or post more recs.
If you want quick starter recs, look for compilation posts titled something like 'Sans x Frisk recs' or 'Sans/Frisk h/c' on AO3 and Tumblr — they often mix classics with hidden gems. I love how community recommendations come with personal notes, so you can pick a story based on mood as much as premise. Happy hunting — there are tons of amazing writers out there, and I’m always thrilled when I find another cozy or gut-punch Sans x Frisk fic to share with friends.