How does X count a link?

X wraps every URL with its t.co shortener and counts it as 23 characters, whatever the original length.

Do emoji count as one character on X?

No. X counts every emoji as 2 characters, including emoji combined with skin tones or joined into sequences.

Do attached photos or videos use up characters?

According to X's documentation, media attached through official clients counts as 0 characters.

Can I write posts longer than 280 characters on X?

X offers longer posts to Premium subscribers. The current limit is on X's Premium help page.

Answer

How long can a post on X be?

Quick answer

A standard post on X holds 280 characters; emoji count as two and every link as 23. Premium subscribers can write longer posts.

What it's not

It is not a count of letters on screen. X weights characters, so a post full of emoji or links runs out of room well before 280 visible characters.

X’s developer documentation gives the rule: “Posts on X can contain up to 280 characters. However, not all characters count equally” (X: Counting characters).

How X counts

X uses weighted counting. Latin letters, punctuation and common symbols count as 1. Emoji count as 2, “regardless of complexity”, so a family emoji built from several joined characters still counts as 2. Chinese, Japanese and Korean characters count as 2, which means a post in those scripts holds about 140 characters. Every URL is wrapped in X’s t.co shortener and counts as 23 characters however long the original address is. Auto-filled @mentions at the start of a reply do not count; @mentions you type yourself do. Hashtags count normally, the # included.

For anyone writing across networks, this is the practical difference: a LinkedIn post is limited by how much the reader will read, a standard X post by how much fits. An idea often has to be rewritten for X, keeping its single sharpest claim, rather than cut down from the LinkedIn version.

Longer posts

X lets Premium subscribers publish posts longer than 280 characters (X Help: About X Premium). Everyone can read them. Because the limit and the features attached to it have changed several times, check X’s own page for the current number rather than a figure quoted elsewhere.