Paste long text, pick X, Bluesky or Threads, and get the parts a reply thread would be made of, with a character count and a copy button for each.
0 characters, 0 parts
Each part holds at most the network's limit: 280 on X, 300 on Bluesky, 500 on Threads. The splitter prefers to break at a paragraph, then a line, then the end of a sentence, then a space, and only counts a break if it falls in the second half of the part. Otherwise it cuts hard at the limit. Parts are trimmed of surrounding whitespace.
This is the same algorithm fanout runs when you publish. If you write once in fanout and select X, Bluesky or Threads, over-long text becomes a reply thread automatically (up to 10 posts), and the composer shows the part count as you type. Nothing is numbered or edited for you, so add "1/" style markers yourself if you want them.
Counting is by Unicode code points, as in the character counter. See the character limits guide for the caveats on how X counts.
Write one draft, publish to every network. Card required, cancel anytime, no charge during the trial.
It looks at the part that fits in one post and cuts at the last paragraph break. If there is none in the second half of that window it tries the last line break, then the last sentence end (. ! ? or …), then the last space. If nothing qualifies it cuts at the character limit. Sentence punctuation stays in the earlier part.
280 characters on X, 300 on Bluesky and 500 on Threads, counted as Unicode code points. X counts URLs as 23 characters and some characters as two, so a part near the limit can read differently in X.
fanout publishes at most 10 parts per thread. The tool warns you when your text needs more.
Yes. When you publish text that is over the limit to X, Bluesky or Threads, fanout splits it with this same logic and posts the parts as a reply chain. You only need this page if you post by hand.