Text Splitter

How to split a long post into a thread

Paste it on the left and pick the destination. The posts appear on the right, each within the limit, each already numbered. Clicking one copies it.

The choice is where it is going, not a character count. Nobody decides on 280.

The numbering has to come out of the budget

This is the thing most splitters get wrong, and it is not subtle.

Cut a long post at 280 characters, then append " (1/12)" to each part, and you have twelve posts of 287 characters. Every one of them is rejected. You find out one at a time, pasting them in.

The space for the suffix is reserved here before the first cut is made, which takes a pass or two to settle: how wide the suffix is depends on how many posts there are, and how many posts there are depends on how wide the suffix is.

A post that fits on its own does not get numbered at all, and so does not pay for the reservation. A message of exactly 280 characters stays one post.

Where the cut lands

In order of preference: a paragraph break, a line break, the end of a sentence, a space. A word is only broken when the word itself is longer than the limit, which in practice means a URL.

That order is why a post sometimes comes out well under the limit. Ending on a full stop reads as deliberate. Ending three words into the next thought reads as a machine ran out of room, which is what happened, but there is no reason to show it.

What the limits are

X is 280, Bluesky 300, Mastodon 500, and an SMS is 160 before it becomes two messages and costs twice as much.

Character counting varies more than you would expect. X counts characters in some ranges as two, some platforms count a URL as a fixed length whatever it is, and emoji are counted differently almost everywhere. Counting here is by what you can see, one emoji being one character. A post sitting right on the limit is worth a look before it goes out.

Clean the text before you split it

Text drafted somewhere else arrives with curly quotes, em dashes and sometimes invisible characters, and every one of them counts against the limit. A post that looks short can fail on length for reasons you cannot see.

Run it through the AI text cleaner first. If it came out of a PDF or an email, the line break remover will put the sentences back together before this tool tries to break them somewhere sensible.

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