How to post one video to TikTok, Instagram Reels and YouTube Shorts

You can post the same vertical video to TikTok, Instagram Reels and YouTube Shorts, and one file is usually enough if you export it for the strictest of the three. Most of what changes between the apps is the text around the video: the caption, the title and a few settings.

This guide covers the manual route, which costs nothing and needs no extra tools. We make a scheduling tool, so we mention it near the end, but everything before that works without it.

What can stay the same

Export one master file with these settings and all three apps should take it:

• Vertical 9:16, 1080×1920. Instagram recommends 9:16 to avoid cropping or blank space, and YouTube treats square and vertical uploads of up to three minutes as Shorts.
• Three minutes or less. That is the Shorts limit, and Instagram says reels over 3 minutes won't be recommended to new audiences. TikTok allows more, but three minutes is the length that works everywhere.
• MP4, H.264 video, AAC audio, 30 frames per second. Instagram's help page asks for at least 30 FPS, while the publishing APIs of TikTok and Instagram accept 23 to 60.
• Under 300 MB. That is the limit in Instagram's publishing API. The other two allow far more, so if you only post through the Instagram app this one may not apply to you. We couldn't find a stated limit for app uploads.

The full numbers, with the places where official pages disagree, are in our video specs guide.

Keep that master file somewhere safe and upload from it every time. Saving your own video back out of one app and posting that copy to the next one can carry the first app's logo, and Instagram's creator FAQ is blunt about it: "Ditch the watermark! The 3rd party watermark on your reel may be impacting its reach."

What has to change for each app

Sound needs a separate check. Music you add inside one app stays in that app, and music already mixed into your file goes everywhere with it. YouTube warns that copyrighted material in a video made elsewhere can bring a Content ID claim, and a Short over one minute with an active claim is blocked globally until the claim is resolved. If a clip runs longer than a minute, use audio you have the rights to.

The manual route, step by step

Before you open any app

1. Export the master file with the settings above.
2. Write the caption once in a notes app. Keep the first line under 100 characters, because it will also be your YouTube title.
3. Watch the video on your phone and check that no words sit at the very bottom or along the right edge. Each app puts its buttons there. The safe zones section of our specs guide has what the platforms publish.

TikTok, from a computer

1. Go to tiktok.com/tiktokstudio and log in.
2. Click Upload and choose your file.
3. Add the caption and choose a cover.
4. Choose who can watch and whether people can comment, Duet or Stitch.
5. Post it.

TikTok has one trap here: a new post keeps the privacy setting of your previous one. If your last upload was "Only you" because you were testing, the next one will be too, unless you change it.

Instagram Reels, from a computer

These steps follow Instagram's help page:

1. Click Create on the left, then Post.
2. Click Select from computer and choose the file.
3. Click Next. Pick a cover and trim if you need to.
4. Click Next again. Paste the caption, using the hashtags that fit this app.
5. Click Share.

YouTube Shorts, from a computer

These steps follow YouTube's help page:

1. Sign in to YouTube Studio.
2. Click Create, then Upload videos, and choose the file.
3. Use the first line of your caption as the title. Add the rest as the description.
4. Answer the audience and other details questions.
5. Under Visibility, publish now or use the Schedule card to set a date, time and time zone.

If you want them to go out later

Each company has its own scheduler, so you can do all of this ahead of time without paying anyone. You still fill in three separate forms.

• TikTok. TikTok's help page lists scheduling in TikTok Studio and says creator tools are for Personal and Business accounts. Its own Video Scheduler post says 15 minutes to 10 days ahead and mentions a Business account for desktop scheduling. Some creators report 30 days. We couldn't settle it from official pages, so trust what your own upload screen offers.
• Instagram. Meta Business Suite can schedule reels. Your Instagram account has to be connected to it.
• YouTube. YouTube Studio takes a date, time and time zone. A Community Guidelines strike on the channel stops scheduled videos from going out during the penalty.

If you are unsure which hour to pick, our guide on finding your own best time covers what the platforms say and how to test it.

Where Reeladay fits

We build Reeladay, so read this part knowing that. It handles the repeated part of the steps above. You upload the file once, and it checks the file against the limits we know for each app before anything goes out. It can draft a caption per app when you ask, and you edit it before use. You set the schedule, and in the morning you get one summary with views, likes and comments from all three.

What it doesn't do: it doesn't film or edit your video, and it doesn't repost anyone else's. On TikTok you choose who can watch and which interactions are on, each time, with nothing ticked in advance, because TikTok's rules for connected apps require that. Access is by email and we set people up by hand. There is no card form on the site yet.

If you post once a week, the manual route above is fine and you may not need any tool. Other schedulers cover this ground too: Buffer and Later both advertise TikTok scheduling on their own sites, and Buffer's page lists crossposting to Reels and Shorts. Compare them on the things you'll use every week.