Modern WordPress performance advice almost always includes one recommendation: convert your images to WebP.
On paper, it sounds simple. WebP images are smaller, widely supported by modern browsers, and can significantly reduce page weight. Many plugins promise dramatic speed improvements by automatically converting all images and replacing URLs site‑wide.
In practice, things are rarely that simple.
After working with WordPress sites for years, I’ve seen image optimization become one of the most fragile parts of a site’s stack. Not because WebP is problematic — but because how WebP is implemented matters far more than the format itself.
This is why I decided to build a conservative WebP converter for WordPress.
WebP Isn’t the Problem — Automation Is
A WebP image is just an image. It doesn’t inherently break layouts, distort dimensions, or confuse browsers.
Most of the issues people associate with WebP come from aggressive automation:
- Replacing image URLs globally
- Assuming themes handle responsive images perfectly
- Interfering with
srcset,sizes, or hard‑coded paths - Breaking social previews (
og:image) on platforms that don’t fully support WebP - Introducing CDN or cache edge cases that are hard to debug
Once image URLs are replaced automatically, images stop being “assets” and start becoming logic. That’s when even small mistakes can ripple across themes, plugins, and external services.
For many site owners — especially client sites — this level of risk is unacceptable.
Different Layers, Different Trade‑offs
There are many valid ways to adopt WebP in WordPress:
- Designing with WebP images from the start
- Uploading pre‑converted images manually
- Generating WebP at upload time
- Serving WebP conditionally via
<picture>orsrcset - Letting a CDN handle conversion automatically
Each approach comes with trade‑offs in control, complexity, and risk.
The problem arises when a tool claims to solve everything automatically, without clearly communicating those trade‑offs.
A Conservative Approach by Design
When I started building RW WebP Converter Lite, I made a few intentional decisions:
- Never replace existing image URLs
- Always keep original images by default
- Generate WebP files alongside originals, not instead of them
- Avoid touching front‑end rendering logic
- Follow WordPress core image APIs instead of custom hacks
This approach is not the most aggressive, nor does it promise the biggest synthetic performance gains.
What it does offer is predictable behavior.
If something goes wrong, site owners can disable the plugin and everything still works. Images remain where they were. URLs don’t change. Themes don’t need to be rewritten.
In other words: the plugin should never be a single point of failure.
Why Not Just Upload WebP Images Manually?
That is a perfectly valid approach — and for many workflows, it’s the right one.
However, in real‑world WordPress sites:
- Editors upload images from many devices
- Legacy content already exists in large quantities
- Consistency is hard to enforce
A conservative conversion tool can help bridge that gap without taking full control away from the site owner.
RW WebP Converter Lite as a Reference Implementation
RW WebP Converter Lite exists as a reference implementation of this philosophy.
It focuses on:
- Bulk conversion of existing JPG and PNG images
- Automatic conversion on upload (optional)
- Respecting size thresholds to skip small images
- Minimal assumptions about themes, CDNs, or front‑end behavior
It deliberately avoids advanced features like URL replacement, CDN integration, or format negotiation. Those can be powerful — but they also deserve careful handling and explicit opt‑in.
There Is No Single “Correct” Way
WebP is not a silver bullet. Neither is any plugin.
The right solution depends on:
- Your hosting stack
- Your theme
- Your content workflow
- Your tolerance for risk
My goal with this project is not to replace other solutions, but to offer a safe, predictable option for people who prefer control over automation.
If nothing else, I hope it helps clarify that when it comes to performance optimization, how something is done is just as important as what is done.
RW WebP Converter Lite is available for free on WordPress.org. This article reflects the design philosophy behind the project, not a recommendation that it is the right tool for every site.