In what month and year did TikTok introduce the 'Stitch' feature?

TikTok introduced the Stitch feature in September 2020.

Stitch lets a user select a short segment of another creator’s public video and incorporate it into a new post. The creator then records an original response or continuation, making Stitch useful for commentary, tutorials, jokes, reactions, and question-and-answer formats. TikTok’s launch instructions allowed users to select up to five seconds from the original clip.

Stitch was designed as a companion to Duet, but the two formats work differently. Duet places videos together in a split-screen or paired layout, while Stitch inserts part of the original video into the beginning of a creator’s new video. The original account is credited in the caption, with a link back to the source clip.

A common mix-up is October 2020, because TikTok rolled Stitch out in some international markets after its September announcement. The feature’s official launch announcement, however, was dated September 3, 2020, making September 2020 the accepted month and year.