How to determine the max file upload limit in php


How can the file upload size allowed by php settings be determined withing a php script?


The upload is limited by three options: upload_max_filesize, post_max_size and memory_limit. Your upload is only done if it doesn’t exeed one of them.

The ini_get() function provides you with a short hand of the limit and should be converted first. Thx to AoEmaster for this.

function return_bytes($val) {
    $val = trim($val);
    $last = strtolower($val[strlen($val)-1]);
        case 'g':
        $val *= 1024;
        case 'm':
        $val *= 1024;
        case 'k':
        $val *= 1024;
    return $val;

function max_file_upload_in_bytes() {
    //select maximum upload size
    $max_upload = return_bytes(ini_get('upload_max_filesize'));
    //select post limit
    $max_post = return_bytes(ini_get('post_max_size'));
    //select memory limit
    $memory_limit = return_bytes(ini_get('memory_limit'));
    // return the smallest of them, this defines the real limit
    return min($max_upload, $max_post, $memory_limit);


Answered By – HyperCas

This Answer collected from stackoverflow, is licensed under cc by-sa 2.5 , cc by-sa 3.0 and cc by-sa 4.0

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