get_charset

The mysqli_get_charset() function returns the character set that PHP is using for a given MySQL connection — for example utf8mb4, latin1, or utf8. Knowing the active charset matters because it controls how text is encoded between PHP and MySQL: the wrong charset turns accented letters, emoji, and non-Latin scripts into garbled "mojibake" and is a classic source of ? characters in stored data.

This article explains what the function returns, how to read every field of the result, and the practical reasons you would call it.

Syntax

mysqli_get_charset(mysqli $mysql): ?object

In object-oriented style the same function is available as the $mysqli->get_charset() method.

• $mysql — a connection returned by mysqli_connect().
• Return value — a stdClass object describing the connection's character set, or null if the charset could not be determined.

What the returned object contains

Unlike functions that return a plain string, mysqli_get_charset() returns an object with several fields. The most useful ones are:

Basic usage

Call the function on a valid connection and read the charset property:

<?php
$mysqli = mysqli_connect("localhost", "username", "password", "database");

if (mysqli_connect_errno()) {
    die("Connection failed: " . mysqli_connect_error());
}

$charset = mysqli_get_charset($mysqli);

printf("Character set: %s\n", $charset->charset);   // e.g. utf8mb4
printf("Collation:     %s\n", $charset->collation); // e.g. utf8mb4_general_ci

mysqli_close($mysqli);
?>

We connect with mysqli_connect(), check for a connection error, then read the charset and collation fields off the returned object.

Object-oriented style

If you prefer the OOP mysqli API, use the get_charset() method:

<?php
$mysqli = new mysqli("localhost", "username", "password", "database");

$charset = $mysqli->get_charset();

echo "Charset:   {$charset->charset}\n";
echo "Max bytes: {$charset->max_length}\n"; // 4 for utf8mb4

$mysqli->close();
?>

When would I use it?

• Debugging encoding bugs. When stored text shows up as ? or mangled symbols, confirming the connection charset is the first diagnostic step.
• Verifying a set_charset() call took effect. After calling mysqli_set_charset() you can read it back to be sure the change applied.
• Branching on byte width. Reading max_length tells you whether the connection can store 4-byte characters such as emoji (utf8mb4) or only up to 3 bytes (utf8).

Get the name only

If you only need the charset name and not the full object, mysqli_character_set_name() returns it directly as a string:

<?php
$mysqli = new mysqli("localhost", "username", "password", "database");

echo $mysqli->character_set_name(); // e.g. utf8mb4

$mysqli->close();
?>

Common gotchas

• Don't confuse it with the MySQL character_set_client variable. This function reports the charset PHP is using to talk to the server; it does not change how columns store data — that is fixed by the table/column definition.
• Set the charset explicitly. Relying on the server default is fragile across hosts. Call mysqli_set_charset($mysqli, "utf8mb4") right after connecting, then mysqli_get_charset() should report utf8mb4.
• Accessing properties on null. If the connection failed, the function may return null; reading ->charset on null raises a warning. Always check the connection first.

Conclusion

mysqli_get_charset() returns an object describing the character set of a MySQLi connection — its name, collation, and byte limits. Use it to diagnose encoding problems and to confirm that mysqli_set_charset() applied as expected. For just the name, reach for mysqli_character_set_name().

Practice