Images to WebP

What is Images to WebP?

Images to WebP is a focused WordPress plugin designed to convert PNG, JPG, and GIF files into the modern WebP format. Developed by kubiq, it has been available on the WordPress plugin repository for 7 years. The plugin aims to reduce page weight by over half without sacrificing image quality, directly supporting better Google rankings and faster load times. With 9K+ active installs and a 4.4/5 rating from 32 reviews, it holds a solid 84% five-star approval rate. A notable 13% of users give it a one-star rating, often citing server compatibility issues. The current version is 5.0, last updated on Mar 16, 2026.

This tool operates by generating WebP copies alongside your original files. It never modifies your source images. An automatic test runs after activation to confirm your server supports the format. It works across standard WordPress setups, including multisite networks, and supports both Apache and NGiNX servers.

Key Features of Images to WebP

• Automatic Conversion on Upload — Every new image you add to the Media Library gets a WebP version created instantly.
• Bulk Convert Existing Images — You can select specific folders or convert only missing WebP files across your entire media archive.
• Smart Filesize Comparison — The plugin only keeps a WebP copy if its file size is smaller than the original, preventing bloated conversions.
• Configurable Image Quality — Set the compression level for converted images to balance visual fidelity and file weight.
• Original URL Preservation — Image URLs remain unchanged, so WebP works in <img> src, srcset, <picture> elements, and even CSS backgrounds without breaking cache plugins.
• Developer Hooks — Filters like itw_sizes let you exclude specific thumbnail sizes from conversion, and itw_abspath supports custom folder structures like Bedrock.
• Manual Trigger via convert_image() — Developers can call this method from other plugins to generate WebP versions programmatically.
• Browser Fallback with ?no_webp=1 — Add this parameter to any image URL to load the original JPEG or PNG directly for testing.

Who Should Use Images to WebP?

This plugin suits site owners who want a straightforward method to convert images to WebP without complex configuration. It works for beginners who need automatic conversion on upload, and for developers who require hooks to customize behavior. The 7-year track record suggests stability for typical WordPress blogs, business sites, and ecommerce stores. With 9K+ users, it appeals to those who prefer a lightweight solution over all-in-one optimization suites.

If you already use Fly Dynamic Image Resizer, this plugin integrates directly. Users on shared hosting should verify their server has the GD or Imagick extension with WebP support. The plugin requires PHP 7.0 or higher and WordPress 5.0 or newer. It has been tested up to WordPress 6.9.4.

Installation & Setup

Upload the images-to-webp directory to /wp-content/plugins/ and activate it through the WordPress admin. The plugin automatically runs a server compatibility test upon activation. For Apache users, it attempts to write necessary .htaccess rules; if it fails, on-screen instructions guide you through manual setup. NGiNX users may need to ask their hosting provider to disable direct processing of image static files if a proxy setup exists.

Support & Community

Support data for the last 2 months shows 0 open threads and 0 resolved threads, yielding a 0% resolution rate. This suggests either near-perfect stability or limited developer engagement on the forums. The rating distribution tells a more nuanced story: 84% of users give 4% assign one star. The one-star reviews frequently point to server configuration issues, particularly with NGiNX environments or missing PHP extensions. The plugin’s FAQ covers common troubleshooting steps, including how to check WebP delivery via Chrome DevTools by looking for the webp value in the Type column of the Network tab.