StringLengthCalculator

Character count is the number of individual characters in your string, regardless of how they're stored. Byte size depends on the encoding: ASCII uses 1 byte per character but only supports 128 characters. UTF-8 uses 1 to 4 bytes depending on the character — standard English letters are 1 byte, accented characters like é are 2 bytes, CJK characters are 3 bytes, and emoji are 4 bytes. UTF-16 uses 2 bytes for most characters and 4 bytes for supplementary characters. This distinction matters when working with database column sizes, API payload limits, and file sizes.

JavaScript's .length property counts UTF-16 code units, not Unicode code points. Emoji and some special characters use two code units (called a surrogate pair), so JavaScript reports a length of 2 for a single emoji like 🚀. Python 3's len() counts Unicode code points, giving 1 for the same emoji. To get the code point count in JavaScript, use [...str].length with the spread operator. This tool shows the JavaScript .length value by default since it runs in the browser.

Standard X / Twitter accounts have a 280-character limit per post. URLs are automatically shortened and counted as a fixed length (currently 23 characters) regardless of the actual URL length. Premium subscribers may have higher character limits. The limit is measured in Unicode code points using Twitter's own counting library, which handles some edge cases differently than a simple .length check.

A single SMS segment holds 160 characters when using GSM-7 encoding, which covers standard Latin characters, digits, and common punctuation. If your message includes any Unicode characters — emoji, CJK characters, or characters outside the GSM-7 set — the entire message switches to UCS-2 encoding and the limit drops to 70 characters per segment. Longer messages are automatically split into multiple segments (153 characters each for GSM-7, or 67 for UCS-2, due to header overhead).

No. All text analysis happens entirely in your browser using JavaScript. Your text never leaves your device — nothing is transmitted, stored, or logged. You can verify this by opening your browser's network inspector (F12 → Network tab) while using the tool. The page works fully offline after the initial load.

VARCHAR(255) is a variable-length character column type in SQL databases. The number 255 is a common default because it's the maximum length that can be described with a single byte (2⁸ - 1 = 255), which historically allowed the database to store the string length prefix in just 1 byte. Going above 255 requires a 2-byte length prefix. In modern databases this overhead is minimal, but 255 remains a widely-used convention for fields like names, email addresses, and short descriptions.