How to Use WebP Images on WordPress (2026 Guide)

Images can make your WordPress site look great, but they can also quietly slow it down. WebP Images on WordPress site can reduce image file sizes while maintaining similar visual quality, making it a practical format for faster pages.

Converting one or two images is easy. The real challenge is dealing with the JPGs and PNGs already in your Media Library, automatically handling future uploads, and confirming that visitors are actually receiving WebP files.

In this guide, you’ll learn how to upload WebP images directly, convert them manually, automate conversion with a WordPress plugin, work with existing media, and verify that WebP is being served correctly.

What Is WebP?

WebP is a modern image format developed for the web. It supports:

The main advantage is file size. WordPress Core notes that WebP images can be around 30% smaller on average than comparable JPEG or PNG images, although the actual saving depends on the image.

Google’s own WebP data also shows that lossy WebP can be considerably smaller than comparable JPEG files, while lossless WebP can reduce file size compared with PNG.

That does not mean converting an image to WebP automatically makes it better.

The result depends on:

For example, photographs usually work well with lossy WebP. Transparent raster graphics can benefit from WebP transparency. Screenshots containing small text need more careful compression, while oversized images may need to be resized before format conversion.

So WebP is not a replacement for proper image optimization. It is one part of the process.

Does WordPress Support WebP?

Yes. WordPress has supported WebP uploads natively since WordPress 5.8, released in 2021.

That means you can go to: Media → Add New and upload a .webp file much like you would upload a JPEG or PNG.

There is one important requirement: your hosting environment also needs WebP support through the image-processing library WordPress uses, typically GD or Imagick.

Most modern WordPress hosting environments support WebP. If yours does not, WordPress may show an error when you upload or process the image.

WordPress support also does not mean that every JPEG and PNG in your Media Library is automatically converted to WebP.

By default, WordPress generally keeps generated image sizes in the source format. Developers can change output formats using WordPress filters, but there is no standard Settings → Media switch that automatically converts an existing Media Library to WebP.

For most site owners, that leaves three practical approaches.

3 Ways to Use WebP Images on WordPress

Method	Best For	Main Limitation
Upload WebP directly	A few new images	Does not fix existing images
Convert manually	Small batches and full control	Becomes time-consuming at scale
Use a WordPress plugin	Existing libraries and future uploads	Requires a conversion tool/plugin

A CDN can also deliver optimized WebP dynamically, which we will cover later.

Method 1: Upload WebP Images Directly

If an image is already in WebP format, WordPress 5.8 or newer can normally accept it without an additional image-conversion plugin.

Go to:

Media → Add New

Then upload the WebP file.

This is useful when you already prepare images in Photoshop, GIMP, Squoosh, or another image editor before uploading them.

The downside is obvious: it only helps with images you prepare yourself.

It does nothing for the hundreds or thousands of JPEGs and PNGs that may already exist across an established site.

Method 2: Convert Images to WebP Manually

Manual conversion works well when you only have a handful of images or want precise control over quality.

Using a Browser-Based WebP Converter

For a few images, a browser-based tool such as Squoosh can handle the conversion.

The basic process is simple:

This is perfectly reasonable for a hero image, product photo, or individual graphic.

It becomes less practical once you have dozens or hundreds of files.

Exporting WebP From Photoshop or GIMP

If you already edit images before uploading them, exporting directly to WebP avoids a separate conversion step.

Adobe added full native WebP support in Photoshop 23.2. Current versions can open, create, edit, and save WebP without an additional plugin.

GIMP also supports WebP export, including lossless and lossy options and separate image-quality controls.

Quality should be judged visually rather than by chasing one universal number.

Google’s cwebp encoder uses 75 out of 100 as its default lossy quality setting, which makes 75 a reasonable starting point for many photographs.

Lower settings can produce smaller files, but artifacts may become visible in gradients, flat-colour areas, fine details, or text-heavy images. Compare the output before deciding on a quality level.

Command-Line Conversion With cwebp

For large controlled batches, Google’s cwebp encoder gives you more precise control.

A basic lossy conversion looks like:

cwebp -q 80 input.jpg -o output.webp

For an image that needs its alpha channel preserved at maximum alpha quality:

cwebp -q 90 -alpha_q 100 input.png -o output.webp

For lossless WebP:

cwebp -lossless -q 100 input.png -o output.webp

In lossless mode, the quality value affects compression effort rather than image fidelity.

Command-line conversion is powerful, but it is unnecessary for most WordPress site owners. If your main problem is an existing Media Library and ongoing uploads, a plugin is usually easier to maintain.

Method 3: Convert WebP Automatically With a WordPress Plugin

Manual conversion becomes increasingly inefficient as your Media Library grows.

At minimum, a useful WebP plugin should help you:

This is where a WordPress-native workflow becomes useful.

How to Convert Images to WebP With ThumbPress

ThumbPress can handle new uploads, existing Media Library images, and individual files from inside WordPress.

Which option you use depends on where your images are now.

1. Convert New Uploads Automatically

If you want future JPEG and PNG uploads converted automatically:

1. Go to ThumbPress → Settings → Convert to WebP.
2. Enable Convert During Upload.
3. Click Save Changes.

Once enabled, supported images uploaded afterward can be converted to WebP without manually processing every file.

This is the easiest option for keeping future uploads under control.

2. Bulk-Convert Existing Images

Automatic conversion solves future uploads, but it does nothing for the images already sitting in your Media Library.

That backlog is often where the bigger opportunity exists, particularly on older blogs and ecommerce stores with large product galleries.

To bulk-convert existing images with ThumbPress:

Chunk size determines how many files are handled in each processing batch.

On shared or resource-limited hosting, a smaller chunk size can reduce the chance of a large job exhausting available server resources.

Once processing finishes, review the conversion results before making any decisions about original files.

3. Convert a Single Image

Sometimes the whole library does not need attention.

You may only have one oversized product photo, old banner, or individual image that needs conversion.

To enable individual conversion:

This lets you handle one image without running a bulk conversion across the rest of the library.

Should You Use WebP Conversion and a CDN Together?

It depends on what your CDN already does.

Some image CDNs can automatically detect a visitor’s browser capabilities and deliver WebP or AVIF at the edge while keeping the original image at the origin.

If your CDN already performs dynamic image optimization and format negotiation, you may not need another WebP conversion layer.

Using overlapping optimization features can add complexity without producing a meaningful benefit.

Before enabling both, check:

Use ThumbPress conversion when you want WebP files handled inside WordPress and your Media Library workflow.

Use CDN-level conversion when your delivery platform already handles format negotiation effectively.

You do not need both simply because both options exist.

WebP vs JPEG vs PNG vs AVIF

WebP is useful, but it is not automatically the right format for every image.

Format	Best For	Compression	Transparency	Main Advantage
JPEG	Photographs	Lossy	No	Simple and historically universal
PNG	Graphics, screenshots, lossless assets	Lossless	Yes	Sharp lossless graphics
WebP	Most general web images	Lossy + lossless	Yes	Strong compression with broad browser support
AVIF	Performance-focused modern images	Lossy + lossless	Yes	Often achieves smaller files at comparable quality

AVIF can sometimes outperform WebP in file size, while WebP still benefits from very broad browser and tooling support.

How to Check If WordPress Is Actually Serving WebP

Converting an image is only half the job.

You should also confirm what the browser actually receives.

This is particularly important when a CDN, caching plugin, optimization plugin, or content-negotiation layer sits between WordPress and the visitor.

Check With Browser Developer Tools

In Chrome, Edge, or Firefox:

1. Open the page containing the image.
2. Open Developer Tools.
3. Select the Network tab.
4. Filter requests to images.
5. Reload the page.
6. Click the image request.
7. Check the response headers or file type.

Look for:

Content-Type: image/webp

If you see image/webp, the browser received WebP. Do not rely only on the filename.

A CDN may leave an image URL ending in .jpg or .png while dynamically returning a WebP response to compatible browsers.

That makes the response Content-Type more reliable than the visible URL alone.

Browser Compatibility for WebP in 2026

WebP is supported across current versions of all major browsers, including:

The main compatibility concerns relate to considerably older browser and operating-system combinations.

For example, older Safari installations on pre-Big Sur versions of macOS can still matter for some audiences.

For most modern WordPress sites, browser compatibility is therefore no longer the WebP problem it once was.

Your own audience data should still make the final decision.

Do You Still Need a JPEG or PNG Fallback?

Most WordPress sites no longer need to build a complicated custom fallback system solely for current mainstream browser compatibility.

However, keeping the original image can still be useful.

A fallback may make sense when:

The practical rule is simple:

Do not delete your originals merely because modern browsers support WebP.

Browser compatibility and keeping a recoverable source file are two different questions.

Common WebP Mistakes to Avoid

Assuming Every WebP Will Be Smaller

A WebP version is not guaranteed to beat every well-optimized JPEG or PNG.

Always compare the result instead of assuming conversion equals optimization.

Re-Uploading Images Without Their Existing Metadata

Converting an image file does not itself remove WordPress alt text.

The problem occurs when you download an image, convert it externally, and upload the result as a completely new Media Library attachment.

In that situation, remember to restore relevant information such as:

This matters for accessibility, content management, and image SEO.

Converting a Huge Library Without Testing

Before processing hundreds or thousands of files, test a smaller batch.

Check that:

For a major bulk job, having a current backup is sensible.

Deleting Originals Too Early

Keep the source files until you have verified the converted versions throughout the site.

Originals give you something to return to if the quality setting was too aggressive or another format becomes more appropriate later.

Ignoring Image Dimensions

Turning a 5000-pixel-wide JPEG into a 5000-pixel-wide WebP does not solve the fact that the original image is unnecessarily large for its display size.

Format conversion should work alongside resizing, compression, responsive images, and sensible image dimensions.

Conclusion

Using WebP in WordPress is easier than ever. WordPress has supported direct WebP uploads since 5.8, and most modern browsers support it.

For a few images, use Photoshop, GIMP, Squoosh, or another converter. For larger Media Libraries, ThumbPress can automate WebP conversion for new, existing, or individual images.

If your CDN already handles WebP or AVIF delivery, local conversion may not be necessary.

Before finishing, check three things: file size, image quality, and whether your browser is actually receiving WebP.