How to Create YouTube Shorts from an Existing Video

Your long-form YouTube videos are a goldmine of untapped potential, and turning them into YouTube Shorts is one of the smartest ways to boost your channel's growth. This guide will show you exactly how to transform your existing VODs (video-on-demand) into high-performing vertical videos that grab new audiences, save you time, and drive traffic back to your main content. We’ll cover the best tools for the job, strategies for finding the perfect clips, and tips to make your Shorts stand out.

Why Repurpose Long-Form Videos into Shorts?

You’ve already done the hard work of scripting, filming, and editing a full-length video. Repurposing isn't about being lazy, it's about working smarter. By turning that one video into several Shorts, you give your content new life and unlock a powerful new audience acquisition channel.

• Reach New Eyeballs: The Shorts feed uses its own algorithm, totally separate from the browser and search recommendations. This means your Shorts can reach a massive audience that has never seen your long-form content before. A high-performing Short can introduce your channel to thousands of new potential subscribers overnight.
• Promote Your Existing Library: Have a great video from a year ago that’s not getting many views anymore? A compelling Short can act as a trailer, reigniting interest and sending viewers back to watch the full video. It’s a brilliant way to resurface evergreen content.
• Fuel Your Content Calendar: Instead of having one content piece, you now have five or ten. This keeps your channel active, satisfies the algorithm’s desire for consistent posting, and saves you from the pressure of constantly creating brand new, from-scratch videos.
• Easily Test What Resonates: Shorts are low-risk experiments. You can clip different moments from the same video to see what hooks people the most. The instant feedback helps you understand your audience better and informs your future content strategy.

First, Understand What Makes a Great Short

Before you start slicing up your videos, it's important to know what kind of clips work best in a fast-paced, vertical feed. Not every moment from your long-form video will make a good Short. Keep these principles in mind as you hunt for clips:

• Grab Attention Immediately: You have less than three seconds to stop a user from swiping. Start your Short mid-sentence, with a shocking statement, a controversial question, or an exciting visual punch. The slow, cinematic intro from your main video needs to go.
• Focus on a Single Idea: A Short should be a self-contained morsel of value or entertainment. Don't try to cram three different tips into one 30-second clip. Isolate one question and its answer, one key takeaway, one funny moment, or one step in a process.
• Add On-Screen Text: The majority of Shorts are watched with the sound off. Captions or on-screen text are non-negotiable. They make your content accessible and ensure your message lands, even in silence. Bold, animated captions that highlight keywords perform extremely well.
• Create a Seamless Loop: The best Shorts feel like they could play forever. If you can make the end of your Short naturally flow back into the beginning, you can trick viewers into watching it two or three times. This drives your average view duration way up, a signal to the algorithm that your content is engaging. Optimizing your YouTube Shorts for more views is about understanding these engagement signals.

Method 1: Using YouTube's Built-In "Edit into a Short" Tool

The fastest way to get started is by using YouTube's native tool directly in the mobile app. This method is great for creating simple, quick clips without needing any other software.

Step-By-Step Guide:

1. Open the YouTube App: Navigate to one of your own long-form videos. Make sure you're logged into your channel.
2. Tap the "Create" Button: Underneath the video player, you'll see a row of buttons (Like, Dislike, Share, etc.). Tap on Create.
3. Select "Edit into a Short": A menu will pop up. Choose the "Edit into a Short" option. This will open a new editing interface.
4. Select Your Clip: You'll see your video's timeline at the bottom of the screen. You can grab the handles to trim your clip, which can be up to 60 seconds long. You can also pinch and drag on the video preview above to adjust the framing and ensure the most important subject is in view for the 9:16 vertical format.
5. Add Text, Filters, and Sound: Once you have your clip selected, tap "Next." Here, you can use YouTube’s editing tools to add text overlays, apply simple color filters, or even add music or audio from YouTube’s licensed library (though your original audio will remain).
6. Publish Your Short: In the final step, you'll add your title (don't forget #shorts in the title or description!), set the visibility (Public, Unlisted, or Private), and choose a thumbnail. Tap "Upload Short," and you're done!

The Bottom Line: This tool is excellent for speed and convenience. However, it offers limited editing functionality. You can't add complex animated captions, custom motion graphics, or fine-tune audio levels. For more control, you'll want to use an external editor.

Method 2: Manually Editing for Maximum Impact and Control

For polished, professional-looking Shorts, you'll need a dedicated video editor. This process gives you complete creative freedom over framing, pacing, captions, and graphics. Popular choices include CapCut (free, and fantastic for captions), Adobe Premiere Pro, or DaVinci Resolve.

Step 1: Identify Your "Golden Moments"

Scrub through your long video and hunt for moments that work as standalone clips. You're looking for micro-stories or self-contained points. Here are some things to look for:

• Quick Lists: Did you list "three ways to..." or "five mistakes..."? Each one of those points can likely be a standalone Short.
• Strong Emotional Peaks: Laughter, surprise, frustration - any peak in emotion is an instant hook.
• Single Questions &, Answers: If someone asks a question in your video and you provide a concise answer, that’s a perfect clip.
• Punchlines or Payoffs: Find a moment where you set up a problem or a story and then delivered a satisfying conclusion or punchline. Clip the setup and the punchline together.
• Aphorisms and Quotes: A single, powerful sentence can make for an awesome, shareable Short.

Step 2: Edit and Reframe for a 9:16 Aspect Ratio

Once you have your clips, bring them into your video editor and set up your project in a 9:16 (vertical) aspect ratio (e.g., 1080x1920 pixels).

Since your source video is 16:9 (horizontal), it won't fill the vertical screen. You have a few options:

• Punch In (Crop): The easiest method is to scale up your video so it fills the screen vertically. Then, pan the clip left or right to keep the main speaker or subject in the center of the frame. This is a common and effective technique.
• Use a Template or Blurry Background: Another style is to keep the 16:9 video in the middle of the screen and use the top and bottom space for a title and subtitles. To make the background more visually interesting, you can put a duplicated, scaled-up, and blurred version of the video behind it.

Step 3: Add High-Engagement Elements

This is where you make your Short truly native to the platform. Don't just upload the cropped clip - enhance it.

• Burn In Captions: Use your editing software’s captioning tool (CapCut’s auto-caption function is best-in-class) to generate subtitles. Style them with bright colors, a slight background, and animations that highlight words as they’re spoken.
• Add Supporting Graphics or B-roll: Isolate important words from your captions as on-screen text to provide emphasis. Add relevant emojis or quick-cuts to b-roll footage to keep the viewer’s attention every few seconds.
• Use a Progress Bar: Sometimes a simple animated bar at the top or bottom of the screen that progresses as the video plays can keep people watching until the end.

Step 4: Connect Your Short to the Full Video

The end goal is to convert these new viewers into long-term subscribers who watch your main content. You need to tell them where to go next.

1. Use a Pinned Comment: After uploading your Short, leave a comment like, "Watch the full breakdown and see 4 other tips in our complete video!" and pin it.
2. The "Related Video" Feature: When editing your Short on a desktop, you can go into YouTube Studio, find the Short, and under "Details," you'll see an option for "Related Video." Select the long-form video your Short came from. This creates a clickable link directly on the Short player, making it incredibly easy for viewers to navigate to the full VOD.
3. Verbal Call-to-Action: If possible, end your Short with a quick verbal cue, like: "For the entire strategy, tap the link on this video to watch our full tutorial."

By transforming your long-form content into bite-sized Shorts, you aren't just creating more content, you're building a smarter, more efficient growth engine for your entire YouTube channel. Learning how to create YouTube Shorts effectively is a valuable skill.

Final Thoughts

Creating YouTube Shorts from your existing videos is a proven strategy for maximizing your reach, engaging a new audience, and saving countless hours of content creation. Whether you use the simple, built-in mobile tool or a professional desktop editor, the key is to find those single, punchy moments that can stand on their own and hook a viewer in three seconds or less.

Once you get into the rhythm of clipping and scheduling, you’ll have a consistent flow of content ready to go. To keep it all organized without the headache, this is where we built Postbase. We designed it for content creators juggling short-form video across multiple platforms, with a visual calendar that lets you plan your Shorts, Reels, and TikToks all in one place and trust that they'll publish reliably, every single time.