Undertale Demo OST is the soundtrack album for the Undertale Demo, released May 21, 2013.

All tracks are composed by Toby "Radiation" Fox.

There are 16 tracks in total. Two of these tracks, "Menu" and "End" have been renamed to "Start Menu" and "Good Night" respectively in the complete Undertale Soundtrack while "Empty House" was removed.


No. Title Length Plays
1 Once Upon a Time 1:28 During the intro.
2 Menu 0:32 When starting/loading a truly new file.
3 Your Best Friend 0:23 When the protagonist first encounters Flowey.
4 Fallen Down 0:57 When Toriel intervenes the encounter above.
5 Ruins 1:32 While the protagonist travels the Ruins.
6 Anticipation 0:22 During monster encounters while accompanied by Toriel.
7 Unnecessary Tension 0:17 While you complete Toriel's test of your independence.
8 Enemy Approaching 0:56 While fighting monsters.
9 Ghost Fight 0:56 During fight against Napstablook.
10 Determination 0:50 On the game over screen.
11 Home 2:03 When inside Toriel's home.
12 Heartache 1:48 During the boss fight against Toriel.
13 End 0:32 During most endings.
14 Nyeh Heh Heh! 0:32 In the pacifist ending.
15 Home (Music Box) 2:02 When the protagonist turns off the light/wakes up in their room in Toriel's home.
16 Empty House 3:01 In Toriel's home after killing Toriel.