imagewebp

As of today (end of january 2019), WebP is now supported across all the major browsers (Edge, Chrome, Firefox, Opera).

To convert a PNG image to Webp, we can do this:

<?php

// Image
$dir = 'img/countries/';
$name = 'brazil.png';
$newName = 'brazil.webp';

// Create and save
$img = imagecreatefrompng($dir . $name);
imagepalettetotruecolor($img);
imagealphablending($img, true);
imagesavealpha($img, true);
imagewebp($img, $dir . $newName, 100);
imagedestroy($img);

?>

Function to save any image to Webp

public static function webpImage($source, $quality = 100, $removeOld = false)
    {
        $dir = pathinfo($source, PATHINFO_DIRNAME);
        $name = pathinfo($source, PATHINFO_FILENAME);
        $destination = $dir . DIRECTORY_SEPARATOR . $name . '.webp';
        $info = getimagesize($source);
        $isAlpha = false;
        if ($info['mime'] == 'image/jpeg')
            $image = imagecreatefromjpeg($source);
        elseif ($isAlpha = $info['mime'] == 'image/gif') {
            $image = imagecreatefromgif($source);
        } elseif ($isAlpha = $info['mime'] == 'image/png') {
            $image = imagecreatefrompng($source);
        } else {
            return $source;
        }
        if ($isAlpha) {
            imagepalettetotruecolor($image);
            imagealphablending($image, true);
            imagesavealpha($image, true);
        }
        imagewebp($image, $destination, $quality);

        if ($removeOld)
            unlink($source);

        return $destination;
    }

WebP is not yet supported by Safari, although they are experimenting with it.

Check out https://caniuse.com/#search=webp for the latest support information.

Safari on mac now has limited support (limited to Safari 14+ on Big Sur or later)

Safari on iOS 14.4 and higher has full support