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manifest / performance / image-webp-converter

Image WebP Converter

WordPress plugin: automatically converts uploaded JPG/PNG images to WEBP. By Aaron Belchamber — tools.belchamber.us

by Aaron Belchamber · github.com/aaronbelchamber/image-webp-converter · website

★ 1stars

Install

Download source zip No release zip yet

This is the repository archive. It installs, but the folder name will carry the branch suffix and updates will not flow.

Install straight from GitHub with WP-CLI:

wp plugin install https://github.com/aaronbelchamber/image-webp-converter/archive/refs/heads/main.zip
No built-in updater. New versions won't appear under Dashboard → Updates. Install new releases yourself, or let Git Updater track the repository.
Readme github.com/aaronbelchamber/image-webp-converter ↗

Built by Aaron Belchamber — Business Growth & Cloud Systems Architect A standalone, zero-config WordPress plugin — no dependency on any other project. More: Brandager.com · Belchamber.us · Tools.Belchamber.us

Description

Automatically converts newly uploaded JPG/JPEG/PNG images to WEBP format on the fly, via the WordPress upload pipeline (wp_handle_upload) — not a directory batch-scan. This reduces image file size while preserving quality, improving page load times.

Features

  • Converts JPG, JPEG, and PNG uploads to WEBP automatically as they come in.
  • Preserves transparency for PNG images — and never drops below quality 80 for transparent images specifically, to avoid jagged compression artifacts on hard alpha edges.
  • Corrects EXIF orientation before converting, so photos don't end up sideways.
  • Skips CMYK JPEGs and hosts that can't decode WebP back, rather than risk a broken or corrupted result.
  • Convert Existing Images: safely bulk-convert your current Media Library. Images not yet used anywhere convert immediately; images already in a post's content are converted with their references updated automatically, originals kept for your review; anything referenced from a page builder or widget is left untouched and reported, not guessed at.
  • Cleanup Review screen to move reviewed originals to a holding folder (not deleted) once you're confident.
  • Adjustable quality and an on/off toggle from the WordPress admin (Settings > WebP Converter).

Installation

  1. Upload the image-webp-converter folder to /wp-content/plugins/.
  2. Activate the plugin through the 'Plugins' menu in WordPress.

Usage

Once activated, every new JPG/JPEG/PNG upload is converted to WEBP automatically — nothing else to do. To convert images already in your Media Library, go to Settings > WebP Converter > Convert Existing Images.

Configuration

Quality (0–100) and the automatic-conversion toggle are set at Settings > WebP Converter in wp-admin. No file editing required.

Requirements

  • PHP 7.4+
  • GD extension enabled in your PHP configuration.

Support

Open an issue on this plugin's repository, or contact the developer via belchamber.us.

License

GPLv2 or later — see readme.txt for the WordPress.org-format changelog and FAQ.

Testing against hostile PHP environments

This plugin has four branches no single workstation can reach: a GD build that encodes WebP but cannot decode it, CMYK JPEG handling when Imagick is absent, a lossless path needing PHP 8.1's IMG_WEBP_LOSSLESS, and a PHP 7.4 imagedestroy() call. They are exercised by wp-dev-playground's PHP matrix:

scripts\test\run-php-matrix.cmd

Needs pip install -e E:\ab-code-projects\projects\wp-dev-playground and a container runtime (wpp doctor). All seven variants pass as of 2026-08-27.