# How to post one video to Instagram Reels & YouTube Shorts > Yes, one vertical video works on both. Export a 9:16 file under 3 minutes, tweak the caption per network, & schedule both from one calendar. - Published: 2026-10-10 - Last updated: 2026-10-10 - Author: Sanju (Founder & CEO @ DunSocial) - Topics: shorts, how-to --- Yes, you can post the same video to Instagram Reels & YouTube Shorts. Export one vertical 9:16 file that runs 3 minutes or less, adjust the caption for each network, & schedule both from a single composer. The video is the easy part. The caption is where the two networks differ, because YouTube needs a title & Instagram doesn't have one. ## What makes one file work on both YouTube's rule is the tighter one. Its help center says a video with a square or vertical aspect ratio, up to three minutes long, uploaded on or after October 15, 2024, is categorized as a Short. Instagram Reels take vertical video too, so a 9:16 file that qualifies as a Short is already a valid Reel. Export at 9:16 & keep the important action in the middle of the frame so on-screen buttons & captions don't cover it. Use the clean export from your editor, not a download from another app. A saved clip with another app's watermark looks reposted & is easy to avoid. ## How YouTube treats the caption in DunSocial YouTube needs a title of up to 100 characters. In DunSocial, the first line of your YouTube caption becomes the title & everything after it becomes the description. Instagram uses the whole caption as one block. So write the first line as a clear, searchable title, then add the rest of the caption below it. If you only want one caption, make line one work as both a title & an opening hook. Then trim hashtags for Instagram if you added a pile for YouTube. ## Check the format before you schedule DunSocial checks a Short before it publishes. A video that is landscape or longer than 3 minutes is rejected for YouTube, so you find out while scheduling instead of at publish time. For Instagram, a Reel must be exactly one video. Don't mix photos into a Reel, & don't attach a second clip. ## Schedule both from one calendar 1. Upload the video once to your media library. 2. Select your Instagram & YouTube accounts in the composer. 3. Write the caption & edit each network's version. Put the title on the first line of the YouTube one. 4. Pick a time. To stagger the networks by an hour or more, schedule each one as its own post, so shared followers don't see the same clip twice in a row. 5. Confirm. Nothing the AI drafts goes out without your approval. Shorts published through DunSocial go out as public videos, so check the caption before you confirm. TikTok scheduling is also available as a limited beta connection if you want the same clip there. For the YouTube side in depth, read [the best social media scheduler for YouTube Shorts](/blog/best-social-media-scheduler-for-youtube-shorts). For limits on every network, see [social media post character limits by platform](/blog/social-media-post-character-limits-by-platform-2026). ## Schedule Reels & Shorts together $20/mo flat, or $192/yr, with a 14-day trial & every feature unlocked from day one. Connect Instagram & YouTube, upload once, & schedule both from one calendar. [Start the trial](https://app.dunsocial.com/login). ## FAQ ### Can you post the same video to Instagram Reels & YouTube Shorts? Yes. A vertical 9:16 video of 3 minutes or less is valid on both. Change the caption so YouTube gets a real title on the first line & Instagram gets a caption written for its feed. ### How long can the video be? Keep it to 3 minutes or less. That is YouTube's limit for a Short, so a file under it works on both networks. ### Does YouTube need a title for a Short? Yes, up to 100 characters. In DunSocial the first line of the YouTube caption is used as the title & the remaining lines become the description. ### Should I publish both at the same time? You can: select both accounts & schedule once. Or schedule each network as its own post to stagger them by an hour or more, so followers on both don't see the same clip back to back. ### Can I review before go-live? Yes. A human confirms before anything publishes, & you can check each network's caption in the composer first. ## Sources - [Understand three-minute YouTube Shorts (YouTube Help)](https://support.google.com/youtube/answer/15424877) - [Upload YouTube Shorts (YouTube Help)](https://support.google.com/youtube/answer/12779649) --- ## About this document This is the Markdown representation of https://www.dunsocial.com/blog/post-one-video-to-instagram-reels-and-youtube-shorts. The HTML version of the same page is at the same URL. You can also request Markdown from any page by sending `Accept: text/markdown`. Machine-readable summary of the whole site: https://www.dunsocial.com/llms.txt ## Company - Product: DunSocial, https://www.dunsocial.com - Legal entity: THISUX PRIVATE LIMITED, Chennai, Tamil Nadu, India - Support: support@dunsocial.com - Open the app: https://app.dunsocial.com/login