Capture button

The capture button refers to the square button with a circular indent near the bottom of the left Joy-Con, as well as on the center-left area of the Nintendo Switch Pro Controller.

Overview
The capture button allows the player to capture screenshots and view them in the system's capture gallery, where they can then be edited with customizable text and be posted to either Facebook or Twitter or sent to smartphones.

If the button is pressed, the Switch takes a screenshot of whatever is being depicted on screen, but if the button is held, the Switch saves the last 30 seconds of gameplay as a video, though the latter feature often varies by game. Captured videos can also be edited and posted in a similar fashion.

Super Smash Bros. Ultimate is one of the few games on the Nintendo Switch that does not have the ability to save videos via the capture button, likely due to the feature being redundant as the game can natively save battles with the in-game replay feature, which can convert entire matches into video files. Normal screenshots can still be taken, a feature that is used in conjunction with the series' trademark camera; when taking a snapshot, the resulting picture will be saved directly to the Switch's Album, instead of an album internally within the software as in previous games.