What Is WebP and Why Is It Used on Websites?

WebP is a modern image format created for efficient delivery of images on the web. It was designed to provide smaller image files while retaining useful visual quality, making it an attractive option for websites that need to display many photographs, graphics and other visual content.

Image files can represent a significant portion of the data loaded by a web page. Choosing a suitable format can therefore help developers and website owners manage image file size, loading performance and storage requirements.

In this guide, we will look at what WebP means, how WebP differs from JPG and PNG, when WebP is useful, and what you should consider before converting your images.

What Is WebP?

WebP is an image file format developed for the web. A WebP file can use either lossy or lossless compression, depending on how the image is encoded.

This flexibility makes WebP useful for several types of images, including photographs, website graphics and images that require transparency.

The file extension for WebP images is:

Why Was WebP Created?

The web depends heavily on images. Product photographs, blog images, thumbnails, banners, profile pictures and illustrations can all add substantial amounts of data to a page.

WebP was created as a modern alternative that can provide efficient image compression while supporting features commonly needed for web content.

Instead of treating every image format as equally suitable, a website can select a format that fits the content, visual requirements and browser environment.

WebP vs JPG

JPG has been one of the most widely used formats for photographs for many years. It uses lossy compression and is supported across a very wide range of software and devices.

WebP can also use lossy compression, making it suitable for many of the same photographic use cases. Depending on the image and encoding settings, WebP may produce a smaller file at a similar visual quality.

The exact result is not guaranteed for every photograph. Image content, dimensions, quality settings and the encoder all affect the final size and appearance.

WebP vs PNG

PNG is especially useful for graphics, screenshots, illustrations and images that need transparency. PNG uses lossless compression, which means the stored image data can be preserved without the same type of quality loss associated with lossy compression.

WebP can also support transparency and lossless compression. This means that some graphics that would traditionally be stored as PNG may also be suitable for WebP.

The best choice depends on the particular image and the requirements of the website or application.

Does WebP Support Transparency?

Yes. WebP supports images with transparent areas, which makes it useful for logos, icons, overlays, illustrations and other graphics where a transparent background is needed.

This is important because transparency is one of the reasons designers often choose formats such as PNG. A modern web image workflow can therefore consider WebP for both photographic and transparent content.

Lossy WebP and Lossless WebP

WebP can be encoded using lossy compression or lossless compression.

Lossy WebP

Lossy WebP reduces file size by discarding some image information. It is commonly useful for photographs where a small amount of visual difference is acceptable in exchange for a smaller file.

Lossless WebP

Lossless WebP preserves the image data without the same type of irreversible loss used by lossy compression. It can be useful for graphics, icons and other images where preserving exact details is important.

Why Do Websites Use WebP?

One major reason is image file size. Web pages often contain several images, so reducing the size of each file can reduce the total amount of data required to display a page.

Smaller image files can also be easier to store, transfer and cache. This can be particularly useful for image-heavy websites, online stores, blogs, news sites and content platforms.

However, WebP is only one part of image optimization. Image dimensions, compression settings, responsive image delivery, caching and other techniques also matter.

WebP and Website Performance

Large images can consume a significant amount of network bandwidth. Sending an unnecessarily large original photograph to a visitor's device may require more data than the page actually needs.

Converting suitable images to WebP can be one method of reducing image payload size. The actual performance improvement depends on how the image is encoded, how large the original file is, and how the image is delivered by the website.

Should Every Website Image Be WebP?

Not necessarily. A good image strategy considers the content, required compatibility, visual quality and delivery method.

A photograph, logo, screenshot and technical illustration may have different requirements. The best format can therefore vary between images.

WebP is an excellent option to consider, but it should not be treated as a universal answer for every situation.

When Should You Convert JPG to WebP?

Converting JPG photographs to WebP can be useful when you need modern web-friendly image files and want to reduce file size.

Before replacing your existing JPG images, compare the WebP result with the original. Check dimensions, visual quality and file size rather than relying only on a fixed quality number.

When Should You Convert PNG to WebP?

PNG graphics may also be candidates for WebP, particularly when the image contains transparency or when a smaller web-oriented file is desirable.

As with JPG conversion, compare the final image with the original and make sure important transparent areas, edges, lettering and fine details remain correct.

WebP for Blog Images

Blog websites often use featured images, thumbnails and inline illustrations. These images can appear across many pages, so keeping their dimensions and file sizes under control can be important.

WebP can be useful for blog publishing because it provides a modern image format that is suitable for many photographs and graphics.

WebP for E-Commerce Websites

Online stores can contain hundreds or thousands of product photographs. Large product images can increase storage and transfer requirements.

Using appropriately sized WebP images can help reduce unnecessary image data while keeping product photos suitable for the page.

What About Image Quality?

Image quality depends on more than the file format. Compression level, source image quality, dimensions and encoder settings all influence the final result.

A poorly configured WebP image can still look worse than a properly configured JPG or PNG. The goal is therefore to choose settings that match the intended use rather than simply choosing a format name.

WebP File Size

There is no universal WebP file size. A small icon and a large photograph can both be WebP files while having completely different sizes.

The final file size depends on the image dimensions, image content, compression method and quality settings.

Common WebP Mistakes

One common mistake is converting an image to WebP but keeping unnecessarily large dimensions. A format change alone does not automatically solve every image optimization problem.

Another mistake is using very aggressive compression simply to achieve an extremely small file. This may introduce visible artifacts or remove important details.

It is also important to keep original source files before performing irreversible conversions.

Frequently Asked Questions

Is WebP better than JPG?

WebP can be more efficient for many web images, but JPG remains a widely supported and practical format. The best option depends on the image and the use case.

Is WebP better than PNG?

It depends on the image. WebP supports transparency and lossless compression, but PNG can still be useful for workflows where PNG is specifically required.

Can WebP have a transparent background?

Yes. WebP supports transparency, making it suitable for many logos, icons and graphics.

Can I convert JPG to WebP?

Yes. JPG images can be converted to WebP for compatible web and digital workflows.

Can I convert PNG to WebP?

Yes. PNG images can also be converted to WebP when the resulting format and compression characteristics suit the intended use.

Does converting JPG to WebP always make the file smaller?

No. The result depends on the original image, dimensions, compression settings and encoding method.