Your post is cut off because the timeline was never going to show all of it. It renders roughly the first 280 weighted characters, stops, and puts a Show more link where the rest of your text was. Everything past that point exists, it is published, and it is invisible to everybody who does not tap.
So this is not a bug, a delivery problem or something support can fix. It is a formatting problem and a hook problem, and both are yours to solve. The useful question is not why X cut your post, it is which sentence ended up on the wrong side of the line.
What the timeline actually shows
One boundary, one control. A post in the feed is rendered up to about 280 weighted characters, and then the card ends with a link that expands it. That number is the same as the standard post limit, which has a consequence worth stating plainly: on a standard account nothing is ever truncated, because X refuses a post over 280 rather than publishing a clipped one.
The cut belongs almost entirely to X Premium. A subscription allows a long post of up to 25,000 characters, and the timeline treats it exactly as it treats every other post: it shows the opening and hides the other twenty-four thousand behind a tap. Which is the thing most people do not realise they bought. The subscription raised what you may publish. It did not raise what anybody sees.
There is a second reason a post looks cut short, and it catches people nowhere near the limit: the shape of the card itself. Line breaks, a preview card and attached media all change how much of your text is on screen when a reader decides.
The timeline view and the permalink view
Your post has two lives and they look different. The one you check is the permalink: the focused page you land on after tapping your own post, with the full text, larger type, the timestamp and the view count spelled out. Nothing is hidden there. It is also not where your audience meets your writing.
The timeline is the other life. Smaller type, a fixed-width card between two other people's posts, the text clipped at the boundary, and a reader moving at speed. The reason a post can feel fine when you check it and land badly in the wild is that you have been reading the permalink and everybody else read the card.
Build that into the routine rather than fixing it afterwards: read every draft as it will appear in a feed, at the width most people hold, before it goes out.
Why the first lines are the whole post
A reader in a feed gives a post about a second before deciding. In that second they read the top of the card, which in practice is the first line or two, and everything else in your post is competing for a decision that has already been made.
There is no published number of lines, and there could not be one: how many lines your text makes depends on screen width, font size and where your words wrap. What is reliable is the ordering. The top of the card is read by everybody who scrolled past, the middle by the people who kept reading, and the part behind Show more only by the people who chose it. Three audiences, very different sizes.
Which turns this into an editing rule rather than a formatting one. Whatever you most want a stranger to know goes at the top, before the context and before the setup. The instinct to build toward a point is a good instinct in an essay and an expensive one in a feed.
How line breaks move the cut
Line breaks do two things at once, and the second one surprises people.
First, they cost characters: one each, exactly like a letter. Four blank lines used for rhythm are four characters out of your 280, which is enough to push a post that fitted over the edge.
Second, and more importantly, they change the shape of the card. A paragraph of the same length occupies far less vertical space than the same words broken into five one-line beats with blanks between them. Both may sit comfortably inside the character boundary; only one of them is still on screen when the reader makes their decision. The airy formatting that looks great in a draft is also the formatting that spends the most screen per word.
None of this is an argument against line breaks; a wall of text is worse. It is an argument for checking the rendered card rather than the count, because a count is one number about the whole post and everything here is about shape.
Link cards and media push your text down
Two attachments change the card without costing you a single character.
A post that ends in a link gets a preview card underneath it, generated from the destination page rather than from your post. It is free, it is often the most eye-catching thing in the card, and it occupies the vertical space your next line was going to use. A link in the middle of a post gets no card at all, which is a real difference in how the post looks for zero difference in what it costs. Either way the link itself weighs 23.
Attached media does the same thing, harder. A single image renders in a 16:9 slot in the timeline and is cropped to fit it, so a tall graphic loses its top and bottom and text baked into the edges of a screenshot disappears. The image is usually why somebody stopped scrolling, which is a good trade, but your text is now underneath the thing that earned the attention. The same cropping logic runs on your profile, which is why headers look cropped for the same reason posts look cut.
The cut is measured in weighted characters
One detail moves the boundary in a way nobody expects: the cut does not land on the 280th character you typed, it lands on the 280th character X counted, and X counts some things as more than one.
A link is 23 characters however long it looks, because every link is rewritten through t.co before it publishes. An emoji is 2, whatever number of code points built it. Japanese, Chinese, Korean and Thai characters are 2 each, so those languages reach the cut at roughly half the visible text an English post gets. Paste a long tracking URL into a draft and the visible part jumps backwards by the difference.
The full arithmetic, including what costs nothing, is in how many characters is a tweet. For this guide the only consequence that matters is that you cannot find the cut by counting letters.
The fix, in three rules
None of them require a subscription or a tool.
- Front-load the claim. The sentence you most want read goes first, before the setup and before the context. If your post builds to a point, invert it: the point first, the build afterwards. The reader who taps is the reader who already agreed the point was worth their time.
- Put the caveat after the cut. Qualifications, nuance, the exception and the disclosure all belong in the hidden half, because they are for the person who already decided to read. A post that opens with three lines of hedging has spent its entire visible area apologising.
- Never split a thought across the cut. A sentence that starts above the line and finishes below it reads as a post that broke. Either it fits above, or it starts below. If neither works, the post is too long for one post and it wants to be a thread, where every part gets its own card and its own opening.
That last option is the structural answer to this whole problem. A long post gives a piece one chance in the feed and hides most of it. A thread gives each part its own chance, and the cut stops being something you fight. The rest of the format mechanics, from character weighting to what is worth posting at all, are collected in the X guides.
Frequently asked questions
Why is my tweet cut off?
Because the timeline only ever shows the opening of a post. It renders about the first 280 weighted characters, then stops and offers a "Show more" link, and everything past that point is invisible to anyone who does not tap. It is not a bug: the fix is to move the part that matters above the line.
How much of a post shows before Show more?
About the first 280 weighted characters, the same number as the standard post limit. On a standard account nothing is ever hidden, because a longer post cannot be published in the first place. On X Premium, where a post can run to 25,000 characters, everything after roughly the first 280 sits behind the link.
Does a Show more link reduce engagement?
It adds a step, and every step loses people. Anyone scrolling has to decide to tap before they read the hidden half, so text behind the link reaches a fraction of the people who saw the post. Nothing is penalised for having a Show more, but a claim below it is a claim most of your audience never read.
Why does my post look shorter than I wrote it?
Usually because the visible part ends at a line break or a sentence that falls near the cut, so the post reads as though it stops mid-thought. Line breaks, a link preview card and attached media all change how much text is on screen before a reader has to act. Previewing at phone width shows the shape a character count cannot.
Do line breaks count as characters on X?
Yes, one each, and so do trailing spaces. Four blank lines used for spacing are four characters out of your 280, and they also consume vertical space in the card, which pushes more of your text toward the cut.
Should I post a thread instead of a long post?
For anything that is a sequence of points, yes. Each post in a thread is its own item in the timeline with its own opening, so an eight-post thread has eight chances to be read. A 25,000 character long post has one, and still shows only about 280 characters to anyone scrolling past.