Video and pictures can be split on Snapchat. Moreover, you can undo splitting in a video or picture before saving it. These are the steps to undo a split on Snapchat.
Step 1: Select a snap, tap over it and drag the corners to trim it.
Step 2: Tap on the scissors icon and again drag up to split the picture
Step 3: On the right side, you will see an icon to remove the splitting; tap on it if you want to remove any changes from your snap. In this way, you can easily undo your trimmed video or split snap.