Turn a Long Video into Short Clips with AI

Works withChatGPT Claude Gemini Grok

You’ve recorded a 40-minute interview, webinar or YouTube video, and somewhere inside it are five or six moments that would make great short clips. Finding them by scrubbing through the timeline takes hours, and that’s before you’ve cut, captioned and reformatted them for vertical video.

AI speeds up the slowest part: finding the moments. Paste a transcript into a chatbot and it can pick out self-contained segments with a strong hook, suggest start and end points, and write titles and captions. Dedicated clipping tools go further and cut the video automatically, but you’ll still want a human eye on the final edit. This guide takes about an hour for a batch of clips.

Quick answer: Get a transcript of your video with timestamps, paste it into an AI chatbot and ask it to find five to eight self-contained moments of 20–60 seconds with a strong opening line. Check each suggestion in your editor, cut the clips, reframe them to vertical 9:16, add burned-in captions and a hook in the first second, then write a short title and caption for each platform.

What you’ll need

Your long video, podcast recording or livestream
A transcript with timestamps (YouTube, many editors and transcription tools can produce one)
A video editor that supports vertical video, such as CapCut, DaVinci Resolve, Premiere Pro or your phone’s editor
An AI chatbot such as ChatGPT, Claude, Gemini or Grok
About an hour for five or six clips

Step-by-step: from long video to short clips

Get a timestamped transcript. Export captions from YouTube Studio or your editor, or use a transcription tool. Timestamps are what let you jump straight to each moment.
Ask the AI to find the moments. Paste the transcript and ask for segments that make sense on their own, start with a strong line and end on a clear point (prompt 1). Good clips often contain a surprising fact, a strong opinion, a quick tip or a funny story.
Check each suggestion. Jump to the timestamps in your editor and watch. Sometimes a great line on paper falls flat on screen, or relies on context from earlier.
Tighten the hook. The first one or two seconds decide whether people keep watching. Trim any “so, um, yeah” from the start, or ask the AI for a text hook to show on screen (prompt 2).
Reframe and caption. Crop to vertical 9:16, keep the speaker’s face in frame and add burned-in captions, because many people watch without sound. Check captions for misheard words.
Write titles and captions. Ask for a short title, an on-screen hook and a platform caption for each clip (prompt 3). Tweak them in your own voice.
Schedule and learn. Post clips over a week or two rather than all at once. After a few weeks, paste in your view and retention figures and ask the AI what your best clips have in common (prompt 4).

Copy-paste prompts

1. Find the best clips in my transcript

Here is a timestamped transcript of my [VIDEO / PODCAST / WEBINAR] about [TOPIC] for [AUDIENCE]: [PASTE TRANSCRIPT]
Find 5–8 moments that would work as standalone vertical clips of 20–60 seconds. For each, give: start and end timestamps, the opening line, why it works (tip, story, strong opinion, surprising fact), and any context a viewer might be missing. Rank them from strongest to weakest.

2. Sharpen the hook

Here's the opening of a short clip: "[FIRST TWO SENTENCES]". The clip is about [TOPIC]. Suggest 5 on-screen text hooks of under 8 words that would make someone stop scrolling, without being misleading or clickbait. Also tell me if I should trim the first sentence.

3. Titles and captions for each platform

For this clip: [DESCRIBE CLIP AND KEY POINT]
Write: a YouTube Shorts title (under 60 characters), an Instagram Reels caption (under 150 words with one call to action), a TikTok caption (short, conversational) and 3–5 relevant hashtags. Match this tone: [YOUR TONE].

4. What makes my best clips work?

Here are my clips with views, average watch time and retention: [PASTE DATA AND CLIP DESCRIPTIONS]
What do the best-performing clips have in common (topic, length, hook type, format)? What should I do more and less of? Give three specific changes to test in my next batch.

Recommended tools

ChatGPT: good at scanning long transcripts and suggesting clip points and hooks.
Claude: handles very long transcripts well and explains its picks clearly.
Gemini: works well with YouTube and Google Drive content.
Grok: quick for hooks and trending angles.
YouTube Studio: create Shorts from your own long-form videos and export captions.
AI clipping tools built into many video editors: can auto-detect highlights and reframe for vertical, but check every cut.

Tips and mistakes to avoid

Don’t trust timestamps blindly. Transcripts can drift by a few seconds. Always watch the clip.
Avoid clips that need context. If a viewer needs the previous five minutes to understand it, it won’t work as a short.
Check captions carefully. Automatic captions often mangle names, numbers and jargon.
Respect other people’s content. Only clip videos you own or have permission to use, and ask guests if they’re happy to appear in clips.
Don’t mislead. A hook that promises something the clip doesn’t deliver hurts trust and watch time.
Keep the face in frame when cropping to vertical. Auto-reframe sometimes cuts off heads.
Link back to the full video where the platform allows, so interested viewers can watch more.

FAQ

How long should short clips be?

Many effective clips are between 20 and 60 seconds, though each platform allows different lengths. Make it as long as the moment needs and no longer.

Can AI cut the video for me automatically?

Some tools can detect highlights, cut, reframe and caption automatically. They save time, but results vary, so review each clip before posting.

Will posting clips hurt views on my long video?

Clips often act as trailers, sending curious viewers to the full video. Add a link or mention where to watch the whole thing.

Try it yourself with ChatGPT

Here is a timestamped transcript of my [VIDEO / PODCAST / WEBINAR] about [TOPIC] for [AUDIENCE]: [PASTE TRANSCRIPT]
Find 5–8 moments that would work as standalone vertical clips of 20–60 seconds. For each, give: start and end timestamps, the opening line, why it works (tip, story, strong opinion, surprising fact), and any context a viewer might be missing. Rank them from strongest to weakest.

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