It is possible to define this constant in your file
config/mes_options.php (see the article dedicated to it)
Important
For this width limitation to be taken into account, you must also give a value to the constant _LOGO_MAX_HEIGHT.
- Default value: 0
example :
// Logos larger than 500 pixels wide will not be registered.
define('_LOGO_MAX_WIDTH', 500);
When this constant is set to 0 (zero), SPIP does not carry out a check when the logo is uploaded.
See also: _LOGO_MAX_SIZE and _LOGO_MAX_HEIGHT.