Post one video to Instagram, YouTube and TikTok — in one press
The worst part of making short videos isn't making them. It's uploading the same clip three times, into three apps, writing the caption three times, and trying to remember which one you already did.
Start free →Free plan, no card needed.
How it works
- Connect your accounts once — Instagram, YouTube, TikTok, Bluesky, Mastodon.
- Cut or upload your clip. OnceCast can split a long video into platform-shaped clips first, on your own device — that part is free and needs no account.
- Write one caption — or press the AI button and get one written in your voice, trimmed to fit each platform's limit.
- Press send. The clip uploads once, then goes out to every platform you ticked. Or set a time and let OnceCast publish it for you.
Scheduled posts go out without you
Pick a time and close your laptop. Publishing happens on OnceCast's server, not in your browser, so a post scheduled for 7pm on Thursday goes out at 7pm on Thursday whether you're at your desk, asleep, or on a train.
And if something fails — a platform rejects a file, a token expires — you see it. A failed post shows the error and a retry button. Silent failures are the most common complaint about scheduling tools, so we made ours loud.
It remembers how you post
OnceCast remembers which platforms you usually send to, so the next clip is one tick and one press. If you always post Reels and Shorts but rarely TikTok, it stops asking.
Honest limits
- Each platform's own rules still apply. Video length, aspect ratio and file size limits are theirs, not ours — a clip that breaks TikTok's rules will still be rejected by TikTok.
- Facebook and Threads aren't live yet. They're built and waiting on Meta's app review.
- You need to connect each account — we can't post to something you haven't given us permission for, which is as it should be.
- Nothing posts without you. There's no autopilot mode that invents content and fires it off. You approve or schedule everything.
Questions
Do I need a separate caption for each platform?
No — one caption, trimmed to each platform's limit. You can still tailor them if you want to.
Does my computer need to stay on?
Not for scheduled posts. Those publish from our server.
Is it free?
There's a free plan with no card. The clip splitter is free forever and needs no account at all.
What else comes with it
Posting is one part. OnceCast also pulls your comments into one inbox and drafts a reply in your own voice for you to approve, finds your best clip moments, writes titles, hashtags and newsletters, and will tell you what to post this week if you're stuck.
See everything OnceCast does →