How to turn a long post into a thread on X, Bluesky and Threads

When a thread is the right call

Cutting a post down is usually better when it has one point. A thread is better when the text has several steps or several short ideas that each stand on their own, such as a list of lessons, a walkthrough or a short story.

If you are unsure, try the short version first. A post that survives a cut to one post is stronger than a thread nobody reads past the second reply.

What fanout does with long text

On X, Bluesky and Threads, text that is over the network's limit is published as a chain: the first part is the post and the rest follow as replies to it. Each part is held to that network's own limit, so 280 characters on X, 300 on Bluesky and 500 on Threads.

This applies to those three networks only. On every other network an over-limit post is flagged in the composer and has to be shortened, or given its own version, before you can send it.

The split is made per network from the same text. If you publish one long draft to X and Threads, X gets more parts than Threads because its limit is lower.

Where it cuts

fanout fills each part up to the limit, then looks back for the best place to end it. It prefers, in this order:

• a blank line between paragraphs
• a line break
• the end of a sentence (a full stop, exclamation mark, question mark or ellipsis followed by a space)
• a space between words

When the cut is not clean

A break only counts if it falls in the second half of the part. If a paragraph break exists but only near the start of the part, fanout moves on to the next kind of break. When there is no usable break at all, such as one very long unbroken string, it cuts exactly at the limit.

In practice: if your paragraphs or sentences are shorter than the limit, parts end where you would expect. Long paragraphs without full stops are where you get an ugly cut.

What you see in the composer

While you type, the counter next to the character count shows how many posts the text will become, for example "3 posts, rest as replies". It shows the count, not the exact cut points, so write in clear paragraphs and the cuts will follow them.

If you give a network its own version in its tab, the count for that network follows that version.

The 10-post ceiling

A thread is capped at 10 posts per network. If the text would need more, the composer flags that network and the post cannot be sent until you shorten it. On X that is 2800 characters at most, and fewer in practice because cuts at paragraph and sentence breaks leave parts shorter than the limit.

If you are near the ceiling, a thread is probably the wrong format. Consider publishing the full text where there is room and linking to it.

Media, numbering and signatures

Images or a video attached to the post go on the first post of the chain only. The replies are text.

fanout does not add numbering such as 1/ or 2/ to the parts, and it does not add a closing line. If you want numbers, you would have to type them yourself, and since the cut positions depend on length that is awkward. Writing each paragraph so it reads on its own works better.

If an account has a signature set, the composer includes it in the length it checks, so the signature counts toward the text that gets split.

Write it so it splits well

If you plan the thread deliberately:

• Put the point in the first paragraph. That part is the only one most people see in a feed.
• Keep each paragraph under the smallest limit you are posting to, so each one can be a part by itself.
• Separate ideas with a blank line. That is the cut fanout prefers most.
• Do not rely on a reply starting with "and" or "so". Each part should make sense if someone lands on it alone.
• Check the post count in the composer, then read every network's tab before you publish.