Fox has said he created Sans with "special inspiration" from J. N. Wiedle, author of the webcomic Helvetica—a series about an eponymous skeleton named after the Helvetica typeface.

[4] When Fox first conceived the character, he intended for Sans to make more skeleton puns, but ultimately didn't think this was humorous enough, so he dropped the idea.

The final Japanese version had Sans's dialogue communicated in a "cutesy irreverent typeface" that one might find used in stylized advertisements or on a television variety show.

He then speaks yakuwarigo-style language, sounding something like a male anime or manga character with very masculine expressions such as ze, zo, sa and other "macho" forms.

However, in contrast to the "macho male" stereotype, Sans probably comes across, to a Japanese speaker, as less "commando" and more just like a 'goofy' boy because of his persistent use of the childish oira and anta.

Near the climax of the game, Sans invites the player to eat at a restaurant with him, where he explains how he befriended Toriel behind the large door in Snowdin.

[14] As the game progresses, Sans's behavior is modified to fit different scenarios, based on how often the player opts to kill the monsters in each area.

[19] In the online game Among Us (2018), Sans's hoodie appears as a cosmetic belonging to the Cosmicube event called "Indie Hour", which also featured other characters from Undertale.

[30] Leah Donato of Dualshockers wrote that Sans was the best character in the game, stating her feeling he brings "comedic relief that is sorely needed".

"[32] Destructoid writer CJ Andriessen—who thought that he was too late to play Undertale—wrote that Sans's appearance in Smash Bros. had increased his desire to try the game.

As argued by Elvery, the interactions with Sans encourage the player to take care in their treatment of the game world, and PSIs foster a sense of mutual understanding.

Hatred for the fandom has also appeared in the form of what have been described as "cringe-worthy videos" that feature a graphic representation of the two brothers, Sans and Papyrus, sometimes engaging in romantic and sexual activity.

[16][46] In 2020, the Australian television network ABC News used the "Sans" Undertale OST theme when discussing the origins of coronavirus and its impact on life in China.

[47] In a paper titled Ethics at Play in Undertale (2018), author Frederic Seraphie compared the battle with Sans to breaking the fourth wall.

Seraphie considered this final boss battle as a metaphorical way to "break" Undertale and concluded that it had the most discordant story-line of the game.

[48] In 2015, Ben Davis of Destructoid praised Sans's unexpected appearance on The 700 Club, a Christian television program hosted by Pat Robertson.

The show had received a viewer's question that referred to "several pictures of a strange cartoon skeleton with one glowing blue eye and wearing a hoodie".

"[49] In 2019, professional wrestler Kenny Omega expressed his love for Undertale by dressing as Sans for the October 30 episode of All Elite Wrestling: Dynamite.

[50] On September 8, 2022, Sans was chosen as the "Ultimate Tumblr Sexyman" (referencing an online slang term for fictional characters who garner romantic and/or sexual interest from a large fanbase despite not being conventionally attractive) via a three-day tournament bracket of polls on Twitter.

[51] Toby Fox responded to the results by writing a short fan fiction that humorously dramatized Reigen's attempts at surpassing Sans in the poll.

[52] In the piece, Fox wrote that "Sans won by doing literally nothing, while Reigen cheated his way to the finals, only to come against the hard truth that Tumblr is not into conventionally attractive men".

The "Ultimate Tumblr Sexyman" poll ended on the same day as the death of Elizabeth II, leading to jokes connecting the two events.