Tweet / X Length Checker

Weighted characters, not characters

The 280 limit is not a count of characters. Characters are weighted: most Latin, Cyrillic and Greek text counts as 1 per character, while CJK and emoji count as 2. A post that is comfortably inside the limit in English can be over it in Japanese at half the visible length.

URLs are the other adjustment. Every link is counted at a fixed length regardless of how long it actually is, because the platform shortens them — this tool applies 23 characters per URL when that option is on. A 200-character URL costs 23; so does a 20-character one, which means shortening a link yourself buys nothing. The same goes for a domain typed without http://: X turns "example.com" into a link, so it costs 23 rather than its 11 letters, and a filename such as "notes.md" can surprise you the same way because .md is a country domain.

Long-form mode raises the ceiling to 25,000 for accounts that have it, using the same weighting rules.

Thread splitting

When text runs over, the tool splits it into a thread rather than truncating, breaking at sentence boundaries where it can so no post ends mid-clause. Optional numbering costs characters in every post, which is why enabling it can change how many posts you end up with.

Worth planning for: the first post is what most readers see and what gets shown in previews, so it has to work standing alone. A thread whose first post is a fragment of a longer thought performs badly regardless of how good the rest is.