The X character limit, both answers.

On a free X account a post stops at 280 characters. The composer will not let you publish past it, and the API refuses it too, so this is a hard wall rather than a guideline. On X Premium the same post can run to 25,000 characters, with everything after the opening hidden behind a Show more. Reading a longer post needs no subscription; writing one does.

Both numbers are worth knowing even if you only have one of the accounts, because they explain what you see in the timeline. A thread is usually somebody working around 280. A wall of text that ends in Show more is somebody who pays.

The count is characters, not words, and not every character costs one.

• Letters, digits, spaces and punctuation each cost one.
• An emoji usually costs two, and some flag and skin-tone emoji cost more, because they are several code points joined together.
• Accented and non-Latin letters can cost more than one, so the same sentence in Arabic, Japanese or Hindi will not measure the same as in English.
• A link is shortened by X on its side, so a long URL does not eat the post, but it does not cost nothing either.
• A line break is a character. A post with airy spacing spends part of its budget on the spacing.

The practical consequence: a take that measures a handful of characters under the cap in a text editor is worth checking in a real counter before you publish it, especially if it carries emoji or a link.

Premium raises the ceiling and changes very little else. The composer keeps counting past 280; media, polls and hashtags work the same way. Two limits are worth knowing before you rely on long posts.

• An account you mention after the first 280 characters is not notified, so a thank-you buried at the end of a long post does not reach the person it thanks.
• Longer posts cannot be drafted or scheduled on the web composer, which matters if you write in the morning and post in the evening.
• The opening still has to earn the Show more. A long post is read like a short one until someone decides to expand it.

There are three honest options, and cutting words until it fits is only one of them.

Cut it down

Most takes that run to 400 characters are a 240-character take with a wind-up. The first sentence is often throat-clearing, the last often repeats the middle. Read it aloud and remove whatever you would not say.

Split it into a thread

A thread is right when the take has genuinely separate parts: a claim, the evidence, the consequence. It is wrong when it is one idea sawn into pieces, which reads as padding. Where you break matters more than how many pieces you get: break at the joints of the argument, never mid-thought, and never mid-link. The free thread splitter shows the tweets a take becomes before you post it.

Write it long, on Premium

A long post suits a piece that would lose its shape in fragments: a story, a walk-through, a correction. The opening still does the work of a first tweet, because everything after it is behind Show more.

The choice is about how people read, not about what you can technically do. A thread is a set of small arrivals: each tweet shows up on its own, can be quoted on its own, and gives a reader a place to jump in. That is an advantage for an argument built of steps and a disadvantage for a story, which is why a long post often lands better for a narrative even though a thread reaches more timelines.

One habit is worth more than the rule: decide before you write, and write for the shape you chose. A take written as a paragraph and then chopped into tweets reads chopped, and a thread padded into a long post reads padded.