Undertale has a Yuri Index of 0.098
Read more about the Yuri Index here
Suggested by anonymous
because i'm obnoxious i wanted to run some additional numbers on this to see just how much of an impact sans specifically had on this. the total amount of m/m in the undertale tag is 20,917 fics, with the amount of f/f sitting at the bottom with only 5,926 fics. if i sort the tag by fics tagged m/m, sans/sans comprises 43% of the fics, sans/papyrus comprises 14%, and sans/reader comprises 9%. those are the three most written-for ships in that tag. needless to say, that's already pretty bleak. but it gets bleaker.
if i sort the tag instead by f/f, what are the three most written-for ships? alphys/undyne, predictably, is at the top, comprising 51% of the tag. the second is, inexplicably, sans/reader, which weighs in at 23%. and last is toriel/asgore, making up 11% of the tag. (in case you're wondering, sans/sans makes up 7%.)
so basically,
