How the post preview works
What it checks
For each of seven networks the tool finds the point where the text is cut, shows the visible part highlighted next to a plain phone mockup, and counts the hidden part. It also checks whether your first sentence or first line ends before that point, because a hook that is cut off loses most of its readers.
The mockup is generic on purpose. It uses no network logos or interface copy, only the text layout that matters: where the text ends and "more" begins.
The rules it applies and where they come from
Documented limits, checked October 2026: X 280 weighted (each URL counts 23, each emoji 2, CJK characters 2, per X's docs on counting characters), Instagram caption 2,200 (Meta's Graph API reference), TikTok caption 2,200 (TikTok's Content Posting API reference), Threads 500 (Meta's Threads API) and Bluesky 300 graphemes (the app.bsky.feed.post lexicon). LinkedIn 3,000 and Facebook 63,206 are widely documented but not verified against an official page this month. The length of an X long post is not verified.
Fold points are different. Instagram about 125 characters, LinkedIn about 3 lines or 210 characters, Facebook about 477 characters, TikTok one to two lines and Threads about 5 lines are observed, approximate behaviors. The networks do not document them and can change them without notice.
Limitations
Wrapped lines depend on screen width, so the line-based folds only count lines you broke yourself. Length is counted the way each network counts it: weighted for X, graphemes for Bluesky, UTF-16 units for TikTok and code points elsewhere. The fold positions use code points. Always check the live post in the app after publishing.
Frequently asked questions
Where does Instagram cut a caption?
In the feed, a caption collapses after roughly the first 125 characters and shows "more". Instagram does not publish that number, so it is an observed, approximate figure. The published limit is 2,200 characters for a caption.
How many characters show on LinkedIn before "see more"?
On mobile, about 3 lines or roughly 210 characters show before "see more". That is an observed, approximate figure, not an official one. The published post limit is 3,000 characters.
Does X truncate posts?
A standard post is capped at 280 characters and shows in full. Longer posts, from accounts that can write them, are observed to collapse behind "Show more" after about the first 280 characters (approximate). X counts by weight: a URL is 23, an emoji is 2 and CJK characters are 2.
Why does Bluesky have no fold?
A post is capped at 300 characters, so the whole post is already short enough to show. The tool flags a post that goes over 300 instead of showing a fold.
Are these fold points official?
Only the posting limits are published by the networks. The fold points are observed, approximate, and every one is labeled that way in the tool. Screen width, font size and app version move them by a few characters.
Do line breaks count toward the fold?
On networks that fold by lines, yes. A blank line takes up a visible line, so a spaced-out hook reaches the fold sooner than the same words in one paragraph. The tool tells you when line breaks are what trigger the cut.