<?php
$url = "http://konachan.com/image/5903a59a96d009821954319810a438fd/Konachan.com%20-%20198471%20apple%20aqua_%28kono_subarashii_sekai_ni_shukufuku_wo!%29%20bed%20blue_eyes%20blue_hair%20food%20fruit%20kono_subarashii_sekai_ni_shukufuku_wo!%20kurripu%20long_hair.png";
$url2 = urldecode($url);
$url3 = explode('/', $url2);
$last = array_pop($url3);
$url3 = implode('/', $url3);
$url3 .= '/'.urlencode($last);
var_dump($url, $url2, $url3, rawurlencode($url2));
var_dump(filter_var($url, FILTER_VALIDATE_URL), filter_var($url2, FILTER_VALIDATE_URL), filter_var($url3, FILTER_VALIDATE_URL));
preferences:
29.35 ms | 402 KiB | 5 Q