B-roll
B-roll is supplementary footage cut into a video to support or illustrate the main A-roll (the speaker on camera). In short-form video, B-roll is typically 1–4 second inserts of relevant imagery, gameplay, screen recordings, or stock footage that visualize what the speaker is describing. Used well, B-roll boosts retention; used to cover the punchline, it kills replay.
The traditional film-school definition of B-roll is "everything that isn't the primary subject." In short-form video, the working definition is narrower: B-roll is the visual support that fills the screen while the speaker continues talking off-camera. It serves three functions — illustrate (show what the speaker is describing), retain (visual variety holds attention), and pace (cuts every 2–4 seconds match short-form viewer expectations).
The most common B-roll mistake in short-form is cutting away to B-roll over the closing line of a clip. Viewers read emotion from the speaker's face — when the punchline lands on a face, the clip resolves emotionally. When the punchline lands on B-roll, the viewer reads "produced content" and bounces. Land closing lines on the speaker; use B-roll for the middle.
AI clip generators don't add B-roll automatically by default — the source footage either has B-roll already (cut by the original editor) or it doesn't. Clipzing.com's clip-export workflow preserves whatever B-roll exists in the source segment.
Related terms
Jump cut
A jump cut is a video edit that removes time between two similar shots, creating a visible discontinuity in the speaker's position or framing. In short-form video, jump cuts compress speech (cutting out pauses, filler words, slow segments) to maintain the fast pacing the format demands. A well-executed jump cut every 3–5 seconds keeps retention high.
Aspect ratio
Aspect ratio is the proportional relationship between a video's width and height, expressed as width:height. The dominant short-form ratio in 2026 is 9:16 (vertical, 1080×1920) used by TikTok, Instagram Reels, and YouTube Shorts. Long-form video uses 16:9 (1920×1080). Square 1:1 is used by LinkedIn and Instagram feed.
Auto-reframe
Auto-reframe is an AI feature that converts a video from one aspect ratio to another by tracking the subject (typically the active speaker's face) across frames and re-cropping the output to keep the subject centered. The dominant use case is converting 16:9 source footage into 9:16 vertical clips for TikTok, Reels, and YouTube Shorts.
Viral hook
A viral hook is the first 1–3 seconds of a short-form video clip — the line, image, or question designed to stop the thumb-scroll and earn the next 5 seconds of attention. In 2026, hooks that lead with a specific number, a stand-alone declarative sentence, or a contradiction outperform vague openers by an order of magnitude in retention.