What each platform accepts

Four platforms, four sets of rules. yellit does not paper over the differences — it enforces them before a publish starts, so a post fails while you can still fix it rather than halfway through.

PlatformWhat you can postVisibility
TikTok One video per post, uploaded directly from your machine. Public or private, chosen before you publish.
Instagram A single image, a carousel of 2–10, or a Reel. Public.
YouTube One video, as a normal upload or a Short. Public, unlisted, or private.
X Text on its own, or up to four images, or one video. Follows your account's setting.

Where your media has to live

This is the difference that surprises people, so it is worth stating plainly: the platforms disagree about who fetches the file, and it is not interchangeable.

When you publish a local file to Instagram, yellit briefly stages it in our own storage so Meta can fetch it, then deletes the object as soon as the post has been created. From the command line that step is an explicit --upload flag rather than something applied silently, because making your file publicly fetchable for a few seconds is a real consequence and you should be the one choosing it.

Visibility

You choose who can see a post before it goes out, on the publish page or with --privacy. yellit asks each platform which levels your account is actually permitted to use and never sends one it is not — and if the level you asked for is unavailable, the post is placed at the closest permitted one and the result says so, rather than reporting a plain success for something nobody can see.

Two platform rules sit behind that, and neither is ours to waive. TikTok has no unlisted level, so it treats unlisted as private. And until a TikTok or YouTube integration has passed that platform's own audit, uploads through it can be forced private regardless of what was requested — yellit shows a warning saying so instead of hiding it.

Costs you should know about

X charges per post — roughly $0.015, rising to about $0.20 if your text contains a link. yellit will not quietly spend the higher amount: a post with a link needs --allow-link-cost before it will go out.

Which permissions this needs · Publishing from the command line