I took a 4-minute video I posted a few weeks ago and gave it to Claude. A few minutes later, I had three Shorts out of it. Vertical crop, captions and titles, all done. That's usually a full day of editing. I did it in two prompts.
I build useful things like this with AI every week.
Subscribe on YouTubeThe skill is called long-to-shorts, and it's free. You give it any long video, like a YouTube video, a podcast or a webinar. It finds the best moments, makes each one vertical, adds captions, and saves them as Shorts you can post on YouTube, Instagram or TikTok.
You don't need an editing app. Here's how to set it up and how I actually use it.
What you need
- A long video. In the video above, I used one that was already published, because I wanted Shorts out of it.
- A Claude subscription with Claude Code. I'd recommend the $100 plan. The $20 one runs out very quickly. The $100 one on Opus 5.5 medium works really well for this.
- A Mac, Windows or Linux computer. It works on all three.
Step 1: Install the skill
Open Claude Code. Copy this whole message, paste it in, and press Enter:
Install the long-to-shorts skill for me from https://github.com/Ansub/long-to-shorts.
Clone it into ~/.claude/skills/long-to-shorts, read its README.md and SKILL.md, run the setup
for my computer, check it works, and tell me how to use it.Then wait for it to finish. The first time takes a while, because it downloads a large file (about 3 GB).
Step 2: Tell it what to make
Once it's installed, you start it with /long-to-shorts and tell it where your video is. The README shows the simple version:
/long-to-shorts turn ~/Movies/my-video.mp4 into 10 shortsThat's one way to do it. You just tell Claude how many clips you want. Five, six, ten, whatever.
But that's not how I use it. I don't give it a number. I ask it to look at the transcript and pick the moments that are actually worth a Short. This is what I typed:
/long-to-shorts find the video on desktop folder. Find the clips which are valuable and can be converted into short form.Here's why. In the end, we want our Shorts to work for the people watching them. They should get some value out of each one. If they don't, they won't subscribe. They'll feel like you're spamming them.
It takes a bit of time to run, so be patient with it.
Step 3: Check the moments it picked
When it's done, Claude shows you the moments it picked. Say yes, or tell it which ones to change.
Mine came back with five. I asked it if it had read the transcript, and how it got it. It told me every Short it was recommending came straight from the transcript of the video. That matters a lot, because you want Claude to know what the video is actually about.
Then I told it to pick up to three instead of five, add captions, and render them. That was my second prompt. When it's done, it opens the folder with your Shorts and their titles.
How it frames each Short
This is the part I liked most. Before it cuts anything, it marks out the frame with lines, so it knows where everything is.
In my video, I'm in the bottom right corner of the screen. When Claude cut the Short, it moved me to the bottom part of the vertical frame, with the screen recording on top.
The captions
The captions are spot on. Whatever word I'm saying shows up on screen at the exact same time.
It also knows where my face is. On a full screen shot of me, it doesn't put the captions over my eyes, because that would feel weird. And when the layout switches to the screen recording on top and me at the bottom, it puts the captions in the middle of the two. That way people can still see both the screen and me.
Good to know
- Your video never leaves your computer.
- Use 4K if you can. 4K videos give the sharpest Shorts.
- Ask for value, not a number. Telling it to pick the valuable moments from the transcript gave me better Shorts than just asking for a count.
- Got a clip from your phone instead? If you want to turn one vertical clip into one Short, use my other skill, Claude Shorts.
The skill, the install prompt and the full instructions are all on GitHub.
