X post character counter

How X actually counts a post

The limit is 280, but the unit is not the character you typed. X publishes a weighted counting configuration — the same one its own compose box uses — and it works like this: every character gets a weight, weights are summed, and the total is compared against 280. Most characters weigh 1. Everything outside a small set of ranges weighs 2. Links are replaced with a fixed cost before any of that happens.

Why links are always 23

X rewrites every link in a post as a t.co short link, and bills the post for the length of the short link rather than the original. That length is currently 23 for both http:// and https://. The consequence is counter-intuitive but useful: a 400-character tracking URL costs you 23 characters, and a 15-character link also costs 23. Shortening a URL before you post it saves you nothing.

Why an emoji is 2 and not 11

A single visible emoji is often several Unicode code points glued together. 👨‍👩‍👧‍👦 is four people separated by three zero-width joiners — seven code points, eleven UTF-16 units. ❤️ is a heart plus a variation selector. 🇺🇸 is two regional-indicator letters. X counts the whole visible sequence as one item weighing 2. A counter that iterates over code points reports 22 for the family emoji and tells you your post is over when it is not, which is the single most common way these tools get it wrong. This one segments text into grapheme clusters first, so the sequence stays intact.

The caveats worth knowing

• X is the authority, not this page. A real post is validated server-side by X. These rules are X's own published ones, faithfully implemented, but X can change them — its documentation says as much — and a discrepancy is X being right.
• Bare hostnames are the fuzzy edge. X runs the full IANA top-level-domain list to decide whether something.tld is a link. We recognise anything with http:// or https://, anything starting www., and bare hosts on common TLDs. A bare host on an unusual TLD may be counted here as plain text and by X as 23. Writing the scheme in front of it removes the ambiguity.
• Mentions and hashtags are ordinary text. @name and #tag are not reweighted or shortened; they cost exactly their characters.
• Attached media does not consume characters. Images, video and quoted posts do not count against the 280.

If you are over the limit

Two honest options. Cut, or split. If the text genuinely needs the room, the thread splitter breaks it at sentence boundaries and budgets the same weighted count per post, including the numbering prefix — which is easy to forget, because "12/34 " is six characters you no longer have.