Multiposter

YouTube Shorts to TikTok, Automatically

Multiposter posts your YouTube Shorts to TikTok automatically: connect your Google account through the official OAuth screen, connect TikTok the same way, and from then on one upload publishes to both platforms at once. Your original file goes to TikTok through its official Content Posting API — full quality, no watermark, no re-uploading in the app.

Skip the download-and-re-upload routine. Re-downloaded copies are re-compressed, and videos carrying another platform’s watermark get demoted by TikTok’s and Instagram’s recommendation systems. Multiposter works from your clean original export, so every platform receives the exact file you rendered.

The format already matches — a 9:16 Short fits TikTok as-is, and Multiposter validates each platform’s length and size limits before publishing. Start free: 8 uploads a month, no credit card.

Start for free

YouTube Shorts vs TikTok: Formatting at a Glance

FeatureYouTube ShortsTikTok
Ideal length15–60 seconds15–34 seconds
Maximum length3 minutes10 minutes from the app (longer for some accounts)
Caption styleSearch-led: a keyworded title (≤100 characters) plus description does the ranking workHashtag-led: a long caption field where 3–5 relevant hashtags drive discovery

Frequently asked questions

How do I post YouTube Shorts to TikTok automatically?

Connect your Google and TikTok accounts to Multiposter through each platform’s official OAuth screen, then upload your Short once. Select TikTok (and any other platforms), add your caption, and publish or schedule. Multiposter delivers the same file to TikTok through its official Content Posting API — no re-uploading in the TikTok app.

Should I download my Short from YouTube and re-upload it to TikTok?

No. Downloaded copies are re-compressed, and recycled videos that carry another platform’s watermark get demoted by TikTok and Instagram. Upload your original clean export to Multiposter once, and every platform receives the full-quality, watermark-free file.

Does my YouTube Short fit TikTok’s format?

Yes. Both are vertical 9:16 video. A standard Short (up to 3 minutes) is well within TikTok’s upload limit, and Multiposter validates each platform’s length and size limits before publishing, so nothing fails silently.

Do captions transfer from YouTube Shorts to TikTok?

You write the caption once in Multiposter and can override it per platform — useful because Shorts leans on searchable titles while TikTok leans on hashtags. One caption works fine to start; per-platform overrides are there when you want them.

Is this allowed by YouTube and TikTok?

Yes. Multiposter publishes through each platform’s official API — the YouTube Data API and TikTok’s Content Posting API — using OAuth connections you authorize and can revoke at any time. There is no scraping, browser automation, or password sharing.

Is there a free way to try it?

Yes. The Launch plan is free forever — 8 uploads a month, no credit card. Connect Google and TikTok, upload one Short, and watch it go live on both platforms.