You Should Manually Compress Your WordPress Images To WebP

Though the latter is more common, images in the WebP format are smaller than those in the JPEG format. However, most image distribution sites offer downloads in either PNG or JPEG. Programs like MS Paint (still extremely common – I use it myself!) don’t offer the option to save images in WebP. But since WebP saves so much space, converting your images from their native formats is worth it before uploading them to WordPress. I suggest you avoid automatic conversion tools and do this manually. Here are the reasons why.

Why Did WordPress 6.1 Disable Automatic WebP Conversion?

WordPress 6.1 was supposed to release bundled with a new feature – that all newly converted images would be automatically converted to WebP. This way, everyone would use WebP images, reducing the size of their WordPress installations. It also removes the need for additional plugins for automatic conversion and the need to manually compress the images into WebP before uploading them.

But that plan was dropped, thanks to many concerns about the WordPress feature and bug-tracking website. According to the discussion, this change would catch many WordPress users off guard because of the resources required to convert WordPress images to WebP.

WordPress Generates Multiple Images for Each Upload

Many users don’t realize that uploading an image to WordPress generates dozens of sub-images of different sizes. These serve various purposes, like icons, featured images, and more. I find this problematic, as it seems like a very messy solution, particularly since I’m sure the overwhelmingly large number of generated images don’t ever get used.

The problem with automatic WebP conversion is that WordPress would need to generate two sets of images – one for WebP and one for JPEG due to backward compatibility considerations. This doubles the load on the server while uploading images and ironically increases the space used on the server since we’re now storing two image formats instead of just one.

High Resource Usage Would Strain Low-Cost Web Hosting

Many shared web hosts operate on shoestring budgets and don’t have the capacity for sudden extra CPU usage by thousands of their customers that run WordPress. With this change, low-cost web hosts and small businesses can potentially face an unexpected drag on their servers as they strain to process the WebP images. There’s no hard data on how much this would be and how much it would impact shared hosting providers, but the WordPress team clearly can’t take the risk.

Manually Adding WebP Images to WordPress

The best solution is manually converting your images to WebP instead of relying on an automatic tool. For individual images, the best tool I’ve found is Squoosh. As you can see from the GitHub project page, it’s maintained by GoogleChromeLabs, allowing you to see the “before/after” images between WebP and the native format before saving.

As you can see below, the change in size when converting to WebP is immense:

It’s not unusual to see image compression ratios close to 80% with WebP. You can also adjust the quality of the WebP images or specify that the compression must be lossless if you want no compromise in quality, even though I’ve found that the default settings produce images that are indistinguishable from the originals.

Convert Images in Bulk to WebP

For bulk image conversion, I use AnyWebP – a free tool that batch converts images to the WebP format and then sends you a downloaded zip copy of them. Works great for quick conversion of multiple images.

Avoid Automated Plugins

It’s best to avoid WordPress plugins that automatically convert uploaded JPEG and PNG images to WebP. You don’t know if they’re changing the main image or simply saving an additional copy – and ditto for the sub-images. Moreover, it’s best to avoid extra CPU usage. So change your image formats manually using Squoosh, and then upload them!