Free tool

One caption. Every limit.

Type once and watch every network count along with you. The limits are two orders of magnitude apart, X counts links and emoji by its own arithmetic, and TikTok moves its own limit depending on whether you attach a video or photos. Every figure below is live from the registry, not typed into this page.

Nothing leaves your browser. No upload, no account.

Your caption

What counts as a character

Most networks count what you see: one emoji is one character, a link is its full length. X is the exception. It counts every link as 23 characters no matter how long the URL is, and counts most emoji as two. The X row below reflects that.

The limits, and where they come from

Every number here is read from the same registry PostLake's publish path validates against, so it cannot claim a limit the API would refuse. When a network changes its limit, this page changes with it.

Scroll the table sideways to see every column.

PostLake is the social media API for AI agents. One integration publishes, schedules and measures across every major network, and refuses a post that would fail before it costs you anything.

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Post checkerCaption, images and per-network rules, all checked at once. Image size checkerDrop an image, see who accepts it, and convert it to fit in a click. All free toolsEverything here, no signup on any of it.