Most splitters cut your text to 280 and then add “1/7” — pushing every part over the limit they just measured against.
Runs in your browser. Nothing you type leaves this page.
“ 1/7” is four characters. “ 10/12” is six. “ 100/128” is eight. A splitter that fills each part to 280 and appends the counter afterwards produces parts that are 284 or 286 long, and you find out when the third one fails to send. The numbering has to be reserved before the split, and reserved at its widest — a thread that grows past nine parts widens every suffix in it.
X replaces every URL with a t.co link of fixed length, so a link costs 23 wherever it sits. It also must never be cut in half: half a link is not a link, it is noise with a full stop in it.
A cut can also create a link that was not there. Cut example.coma two characters short and what is left is example.co, which X charges 23. So every part is measured again after it is cut, and shortened until the number is true.
A four-person family emoji is four people joined by three invisible characters, and JavaScript’s .length reports 11 for it. Split at the wrong offset and you emit half a family plus a dangling joiner, which renders as a broken glyph. This tool splits on grapheme boundaries, so an emoji is kept whole or moved to the next part.
Given a choice of break points inside the budget, the last sentence end reads better than the last space, and the last space reads better than the exact limit. Nobody notices a good split; everybody notices a part that ends mid-word.
Splitting is one platform’s problem. PostSiete takes the long version once and writes a native draft for each platform you publish to — numbering counted before the split here, the fold marked on LinkedIn, the 125-character cutoff marked on Instagram — then schedules the lot.
Start free — no card → Free plan, then $12/month Pro or $39/month Siete. Flat, not per seat. Self-hostable.The tool above is the same code that runs in PostSiete Lens, a free Chrome extension that splits threads and shows the real character count inside X, LinkedIn, Instagram, Threads and Facebook while you type. No account, no trial. It reads — it never posts for you.
Add to Chrome — free →Because the numbering was reserved from it, and because the split preferred a sentence end over filling the last few characters. Both are deliberate.
Yes — the checkbox above. With it off the full 280 is available to text, and nothing is appended.
Yes. Every URL costs a flat 23 on X regardless of its written length, and links are never split across parts.
No. The splitting runs in your browser; the page makes no network request with your text.
emojiParsingEnabled — complete emoji, including zero-width-joiner sequences, count as one unit.