See the post before you publish it

What it checks

Each card carries its platform's own verdict: how much of the limit the post uses, counted the way that platform counts, whether an attachment breaks a media rule, and the measured character where the feed stops showing the text. The limits are the ones our publishing engine enforces, read from our sourced spec tables, so a tool here cannot quote a number the product does not.

• LinkedIn (its own preview page): 3,000 characters. Counted in Unicode code points: one plain character is one, and a link costs its full length. LinkedIn shows 3 lines in the feed, then "…see more". Reported at about 210 characters on desktop and 140 on a phone - the same 3 lines at two widths.
• X (its own preview page): 280 characters. Counted with X's weighted rules: every URL costs 23 characters whatever its length, and most emoji and CJK characters cost 2. X shows the whole post in the feed - nothing folds, so the 280-character limit is the only cut.
• Instagram (its own preview page): 2,200 characters. Counted in Unicode code points: one plain character is one, and a link costs its full length. Instagram shows 2 lines in the feed, then "… more". Reported at about 125 characters on desktop and 125 on a phone - the same 2 lines at two widths.
• Facebook (its own preview page): 63,206 characters. Counted in Unicode code points: one plain character is one, and a link costs its full length. Facebook shows 3 lines in the feed, then "… See more".

Why the fold numbers never agree

Search "LinkedIn see more character limit" and you get 140, 210 and 250 from three confident pages. All three are right. LinkedIn clamps the post to three lines and puts a link where the rest went, so the character count is whatever those three lines hold - about 210 in a desktop column, about 140 on a phone. No platform documents the threshold, because there is no threshold to document.

So the cards above do not use a number at all. Each one measures its own clamp in your browser, at the width you are viewing, and reports the character it landed on. The figures below are what the better third-party sources report, with the date we last read them - useful as a sanity check on the measurement, never a substitute for it.

• "Roughly 210 characters on desktop and 140 on mobile before the '...see more' prompt truncates the rest" - authoredup.com, checked 2026-08-25
• "Text gets cut off behind a See More button after around 140 characters" - blog.hootsuite.com, checked 2026-08-25
• "Instagram captions are truncated at 125 characters" - sproutsocial.com, checked 2026-08-25
• "Facebook cuts off longer posts with an ellipsis, forcing users to click See More to expand the text - no character threshold given" - blog.hootsuite.com, checked 2026-08-25

Questions

Is this post preview tool free?

Yes. There is no login and no upload: it runs entirely in your browser, and nothing you type or attach leaves your device.

Which platforms does it preview?

LinkedIn, X, Instagram and Facebook here, side by side from one post. Every other platform we publish to - TikTok, YouTube, Threads, Bluesky and Reddit - has its own preview page.

Where does LinkedIn cut a post off with "see more"?

LinkedIn shows 3 lines in the feed, then "…see more". Reported at about 210 characters on desktop and 140 on a phone - the same 3 lines at two widths. That is why the guides disagree: it is a line clamp, not a character count, so the number moves with the width of the column. The preview measures the clamp instead of guessing it.

Does Instagram really truncate captions at 125 characters?

Instagram clamps the caption to 2 lines and puts the rest behind "… more"; 125 characters is roughly what those two lines hold, which is where the number comes from. Front-load the hook and the fold stops mattering.

Do my post and my image get uploaded anywhere?

No. The page does no network call at all: the text stays in the tab, and an attached image becomes an object URL your browser holds and never sends. Close the tab and both are gone.