X (Twitter) Post Preview

The timeline shows the first 280 weighted characters of a post and then stops, with a Show more link underneath. On a standard account that is academic, because anything longer is rejected outright rather than clipped. On X Premium it is the whole game: you can publish 25,000 characters, and everyone scrolling past still reads 280 of them.

Weighted is the word that matters. The cut does not land on the 280th character you typed, it lands on the 280th character X counts, and X counts a link as 23 whatever its length, an emoji as 2 however many code points built it, and Japanese, Chinese, Korean and Thai as 2 each. Paste a long tracking URL into the middle of a draft and the cut jumps backwards by the difference. The character counter explains that arithmetic in full; this page applies it to find the boundary and draws it on the card.

Which makes the practical rule easy to state. Everything that has to land, the claim, the hook, the reason to stop scrolling, belongs above that line. The material below it is for people who already decided to stay. If the sentence you built the post around is sitting in the dimmed half, either move it or split the post into a thread, where every part gets its own impression in the feed instead of one shared between all of them.

A count is one number about the whole post. Most of what goes wrong is about shape, and shape only shows up when something renders it.

Line breaks are the common one. A draft written in a text editor at full window width becomes a different object at 390 pixels: the two line opener you were proud of is four lines, the list you spaced out for rhythm has a blank line stranded at the bottom of the visible area, and the emoji you used as a bullet has pushed each item onto a second line. Nothing about that is visible in a character count, and all of it is visible in a card.

The second is the link. A post ending in a URL gets a preview card underneath it, generated from the page rather than from your post, and that card takes the vertical space your next line was going to sit in. A post with a link in the middle gets no card at all. Neither costs a character, and both change what someone sees before they decide to scroll on.

The third is where the first image lands. A single attached image renders in a 16:9 slot in the timeline and is cropped to it, so a tall graphic loses its top and bottom, and text baked into the edges of a screenshot disappears. The image size guide covers every placement and the crop each one applies, and the 5MB ceiling that applies to all of them.

The second honest use of this tool is illustration. A deck that argues for a change in tone needs to show the tone, a course module about hooks needs an example hook on screen, and a blog post explaining a structure reads better with the structure drawn than described. A rendered card does that job better than a paragraph in quotation marks, and it does it without screenshotting someone else’s account.

The line between that and something else is short enough to state in one sentence. Draw your own draft, or an example that is clearly an example. Never attribute invented words to a real person or a real brand, and never present a mockup as a screenshot of something that was published. Fabricating a post and passing it off as real is misinformation, most platforms remove it on sight, and where it names a real person it is defamation in a lot of places. Every PNG this tool exports is captioned as a mockup, which is there to make the honest use easy rather than to make the dishonest one impossible.

bbuddy is not affiliated with, endorsed by or connected to X Corp. X, the X logo and the verification marks belong to their owner, and the badge in this tool is an approximation drawn for a mockup rather than a copy of theirs.