Caption length checker

Two limits, not one

Every platform in the table below enforces two separate limits, and the one people memorise is the one that matters least.

The hard limit is where the post is rejected. It is generous — 2,200 characters on Instagram, 63,206 on Facebook. You will almost never hit it.

The truncation point is where the app stops showing your caption and replaces the rest with "more". That one is brutal: 125 characters on Instagram, about 210 on LinkedIn, around 100 on TikTok. Everything past it is read only by people who already decided to care.

Hard limits are the ones ReachXpand's own publisher validates against. Truncation points are approximate by nature — they shift with screen width, font size and whether the viewer is on a phone or a desktop.

Write for the first line

If only the first 125 characters are guaranteed to be seen, then the first sentence is not an introduction — it is the whole advertisement for reading the rest. Three things reliably survive the cut:

• A claim, not a throat-clear. "We are excited to announce" spends the entire preview saying nothing. Lead with the announcement.
• A specific number or detail. Concrete beats abstract in a space this small.
• An unfinished thought. A line that genuinely needs the next one is the only honest reason for someone to tap "more".

Where to put hashtags

Hashtags count against the limit and they look like clutter inside the preview window. On Instagram and TikTok, put them at the bottom after a few line breaks, or in the first comment. On LinkedIn, three to five at the end. On X, one or two — at 280 characters each hashtag is expensive.

A note on line breaks

Line breaks cost one character each and are worth every one of them. A wall of text in a feed is skipped; the same words in three short paragraphs are read. Instagram strips trailing whitespace, so use a real character — a full stop or a dot — on the spacer lines if breaks keep collapsing.

Questions