WebpBolt — Fast, Modular Image to WebP Converter for PHP

Convert JPG, PNG, GIF and BMP images to WebP in PHP, with an extensible pipeline for resizing, grayscale, and any feature you add. Lightweight, zero dependencies, built on PHP's native GD extension.

WebP files are typically 25–35% smaller than JPG and PNG, so converting your images makes websites load faster and improves Core Web Vitals.

Features

• Convert JPG, JPEG, PNG, GIF and BMP to WebP
• Modular pipeline — chain transforms (resize, grayscale, ...)
• Pluggable encoders — add new output formats (AVIF, JPEG, ...)
• Adjustable quality (0–100), preserves PNG transparency
• No external dependencies — pure PHP + GD

Requirements

• PHP 8.0 or higher
• GD extension with WebP support

Check WebP support:

php -r "var_dump(gd_info()['WebP Support']);"

Installation

composer require shykat199/webpbolt

Usage

Simple — convert to WebP

use Shykat\WebpBolt\ImageProcessor;

$processor = new ImageProcessor();
$path = $processor->toWebp('photo.jpg');            // -> photo.webp
$path = $processor->toWebp('photo.jpg', 'out.webp', quality: 90);

Modular — chain features, then encode

use Shykat\WebpBolt\ImageProcessor;
use Shykat\WebpBolt\Encoders\WebpEncoder;
use Shykat\WebpBolt\Transforms\Resize;
use Shykat\WebpBolt\Transforms\Grayscale;

$path = (new ImageProcessor())
    ->addTransform(new Resize(800, 800))
    ->addTransform(new Grayscale())
    ->save('photo.jpg', 'output/photo.webp', new WebpEncoder(quality: 75));

Architecture

ImageProcessor  ── the conductor
   ├─ ImageLoader           reads input files
   ├─ Transforms/           features that change the image (implement TransformInterface)
   │    ├─ Resize
   │    └─ Grayscale
   └─ Encoders/             output formats (implement EncoderInterface)
        └─ WebpEncoder

Add a new feature

Create one file in src/Transforms/ implementing TransformInterface:

namespace Shykat\WebpBolt\Transforms;

use GdImage;
use Shykat\WebpBolt\Contracts\TransformInterface;

class Watermark implements TransformInterface
{
    public function __construct(private string $text) {}

    public function apply(GdImage $image): GdImage
    {
        $color = imagecolorallocatealpha($image, 255, 255, 255, 50);
        imagestring($image, 5, 10, 10, $this->text, $color);
        return $image;
    }
}

Then use it: ->addTransform(new Watermark('© Me')). No other file changes.

Quality guide

Quality	Use case
90–100	Photography, minimal loss
75–85	Websites (recommended default)
50–70	Thumbnails, maximum compression

License

MIT