What does PHP strlen() return?

strlen() returns an integer representing the number of bytes in the string. For ASCII strings, this equals the character count. For multibyte strings (UTF-8), use mb_strlen() for accurate character count.

How to check string length in PHP?

Use strlen($string) to get the length. Example: if (strlen($password) < 8) { echo 'Too short'; }

What is the difference between strlen() and mb_strlen()?

strlen() counts bytes, mb_strlen() counts characters. For UTF-8 strings with emojis or special characters, strlen() may return a higher number than the actual character count.

PHP strlen() Function

String Function PHP 4+

The strlen() function returns the length of a string (number of bytes).

Syntax

strlen(string $string): int

Parameters

Parameter	Type	Description
`$string`	string	The string to measure

Return Value

Returns the length of the string in bytes, or 0 if the string is empty.

Try It Online

Output

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More Examples

Basic Usage

<?php
$text = "Hello, World!";
echo strlen($text);  // Output: 13
?>

Password Validation

<?php
$password = "abc123";

if (strlen($password) < 8) {
    echo "Password must be at least 8 characters!";
} else {
    echo "Password length is acceptable.";
}
?>

Empty String Check

<?php
$empty = "";
$whitespace = "   ";

echo strlen($empty);       // 0
echo strlen($whitespace);  // 3 (spaces are counted)
?>

Note: strlen() counts bytes, not characters. For multibyte strings (UTF-8), use mb_strlen() instead.

Multibyte Strings

<?php
$emoji = "Hello! 👋";

echo strlen($emoji);      // 11 (bytes - emoji is 4 bytes)
echo mb_strlen($emoji);   // 8 (characters)
?>

Common Use Cases

Form validation (minimum/maximum length)
Truncating strings
Checking if a string is empty
Padding strings to a certain length

Related Functions

substr() - Return part of a string
str_replace() - Replace occurrences in a string
mb_strlen() - Get string length for multibyte strings

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