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Documentation Index

Fetch the complete documentation index at: https://docs.x.com/llms.txt

Use this file to discover all available pages before exploring further.

Posts on X can contain up to 280 characters. However, not all characters count equallyβ€”emojis, URLs, and certain Unicode ranges have special counting rules.

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Character weights

X uses a weighted character counting system. Most characters count as 1, but some count as 2:
Character typeWeightMax characters
Latin, punctuation, common symbols1280
Emojis2140 emojis
CJK (Chinese, Japanese, Korean)2140 characters
Other Unicode2 (default)Varies
Use the open-source twitter-text library to accurately count characters in your app.

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Emoji counting

All emojis count as 2 characters, regardless of complexity:
EmojiDisplayCharacter countUnicode
πŸ‘ΎSingle emoji2U+1F47E
πŸ™‹πŸ½With skin tone2πŸ™‹ + 🏽 modifier
πŸ‘¨β€πŸŽ€Combined with ZWJ2πŸ‘¨ + ZWJ + 🎀
πŸ‘¨β€πŸ‘©β€πŸ‘§β€πŸ‘¦Family sequence24 emojis + 3 ZWJs
Zero-width joiners (ZWJ) combine emojis visually but don’t add to the count.

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URL handling

All URLs are wrapped with t.co shortener and count as 23 characters, regardless of the original length: 
https://example.com                    β†’ 23 characters
https://example.com/very/long/path     β†’ 23 characters
This applies to any valid URL detected in post text.

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Special cases

ContentCounting rule
@mentions in repliesAuto-populated @mentions at the start of replies don’t count
New @mentions@mentions you add manually count normally
MediaAttached media (via official clients) counts as 0 characters
HashtagsCount normally (# + tag text)

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Text encoding

The X API requires UTF-8 encoding. Character length is calculated using Unicode Normalization Form C (NFC). Example with cafΓ©:
FormBytesCharacters
NFC (composed)c a f Γ©4
NFD (decomposed)c a f e ́5
X normalizes to NFC, so both encode to 4 characters.

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Implementation

Use the official twitter-text library for accurate character counting: 
import { parseTweet } from 'twitter-text';

const result = parseTweet('Hello, world! πŸ‘‹');
console.log(result.weightedLength); // 16
console.log(result.valid);          // true
The library handles all edge cases including emoji sequences, URL detection, and Unicode normalization.

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Resources

twitter-text library

Official open-source library for text parsing.

Configuration file

Character weight definitions and Unicode ranges.