AI video & Shorts glossary
The short-form world has its own vocabulary. Here are the terms that matter for clipping long videos into Shorts, in plain English.
AI video clipping
Software that watches a long video, finds the moments worth sharing, and cuts them into short clips automatically. See our full explainer on AI video clipping.
Short / Short-form video
A vertical, under-a-few-minutes video made for algorithmic feeds like YouTube Shorts, Reels and TikTok, where discovery comes from the algorithm rather than your follower count.
Vertical video (9:16)
Video shaped taller than it is wide, filling a phone screen. 9:16 is the standard aspect ratio for Shorts, Reels and TikTok. FastClip outputs every clip in 9:16.
Aspect ratio
The width-to-height proportion of a video. Horizontal is 16:9; short-form is vertical 9:16. Posting a 16:9 clip with black bars to a vertical feed looks like leftovers and gets skipped.
Animated captions / karaoke captions
On-screen subtitles that highlight word-by-word in time with the speaker, keeping muted viewers reading to the end. FastClip generates them automatically — see AI subtitles.
Hook
The first 1-2 seconds of a Short that decide whether someone keeps watching or scrolls past. Learn to write them in how to write hooks that stop the scroll.
Retention
How much of a video people watch before dropping off. Short-form algorithms reward high retention and clean loops, so tight pacing matters more than length.
Watch time
The total time viewers spend watching your content. Along with retention, it is one of the main signals platforms use to decide how widely to push a clip.
Repurposing
Turning one piece of long-form content into many short clips for social feeds. See how to repurpose long videos into clips.
VOD (Video On Demand)
A recorded stream or video available to watch after it aired — for example a Twitch VOD. The best moments are usually buried across hours; see FastClip for streamers.
Transcription
Converting spoken audio into text. FastClip transcribes the audio to both find the best moments and generate accurate captions in 20+ languages.
Viral clip
A short clip that spreads far beyond your existing audience because it hooks new viewers fast and holds their attention. There is no formula, but strong hooks, captions and volume raise the odds.
Safe zone
The central area of a vertical video kept clear of each app’s buttons and handles. Keeping your subject and captions in the safe zone makes one clip read cleanly on Shorts, Reels and TikTok.
Batching
Producing many pieces of content in one session instead of one at a time. Turning a single long video into up to 10 clips at once is batching — see how to batch a week of Shorts.
B-roll
Secondary footage cut in over the main clip to add visual interest. It can boost retention on talking-head clips, though it is not required to make a Short work.
Reframing
Adapting a horizontal video to the vertical 9:16 frame so the subject stays in view. FastClip cuts to vertical and lets you adjust the framing in the browser editor.
AI Shorts generator
A tool that automatically turns a long video into ready-to-post vertical Shorts. That is what FastClip is — paste a link and get up to 10 clips in about a minute. Compare options on the alternatives page.
Now put the words into clips
Paste one long video and FastClip turns it into up to 10 captioned vertical Shorts in about a minute. Free to start, no credit card.