Why WebP should be your default image format

If your website feels slow, your images are potentially a major reason.

While teams spend time optimising JavaScript, tuning APIs, and refining infrastructure, one of the biggest performance bottlenecks often goes untouched: image formats. JPGs and PNGs are still widely used, but they were designed for a very different web.

Today, there is a better default. WebP.

The invisible performance problem

Images are typically the largest assets on a page. Hero banners, blog images and thumbnails all add up quickly.

A single unoptimised image can outweigh your entire JavaScript bundle.

And unlike code, images scale linearly:

More content leads to more images and slower pages
Slower pages lead to a worse user experience
Poorer user experience leads to lower engagement and search performance

If you are not actively managing image formats, you are likely carrying unnecessary weight.

What is WebP

WebP is an image format developed by Google, designed specifically for the modern web.

In simple terms:

It produces smaller files than JPG and PNG
Maintains high visual quality
Supports transparency, like PNG

It effectively replaces:

JPG for photography
PNG for graphics and transparency

Without the trade-offs those formats bring.

Why WebP is better

Smaller file sizes

WebP images are typically 25 to 35 percent smaller than their JPG or PNG equivalents.

That reduction directly translates into:

Faster page loads
Reduced bandwidth usage
Lower hosting and CDN costs

Better performance

Modern performance metrics like Largest Contentful Paint, or LCP, are heavily influenced by images.

Smaller images mean:

Faster rendering
Improved Core Web Vitals
Better SEO performance

Every kilobyte you remove is one less thing the browser needs to download, parse and render.

Maintains visual quality

At comparable quality settings, WebP is visually indistinguishable from JPG for most use cases.

You are not trading quality for performance. You are getting both.

Supports transparency

WebP also replaces PNG in most scenarios:

Transparent backgrounds
UI assets
Overlays

With significantly smaller file sizes.

Real-world impact

Switching to WebP is one of the simplest ways to improve your site’s performance.

The benefits compound quickly:

Faster load times lead to better user experience
Better user experience leads to higher engagement
Higher engagement leads to improved conversion rates
Improved performance leads to stronger SEO

It is one of the few changes that delivers immediate, measurable gains.

When not to use WebP

WebP should be your default, but not your only tool.

There are still cases where other formats are better:

SVG for icons, logos and line graphics
AVIF for cutting-edge optimisation, with smaller files but less mature tooling
High-end photography workflows where specific formats are required

The key is to be intentional, not absolute.

How to use WebP

Exporting images

Most modern tools support WebP:

Figma
Photoshop
Illustrator
CLI tools like cwebp

Aim for a balance between compression and quality, typically between 70 and 85 percent.

Using WebP in HTML

To ensure compatibility across browsers, use the <picture> element:

<picture>
  <source srcset="image.webp" type="image/webp">
  <img src="image.jpg" alt="Example image">
</picture>

This provides a fallback for older browsers while prioritising WebP.

Using a CDN or CMS

Many platforms now support automatic image optimisation:

Cloudflare
ImageKit
Contentful or other headless CMS platforms

These can:

Convert images to WebP automatically
Serve the right format per browser
Optimise size on the fly

A practical migration approach

You do not need to convert everything at once.

Start with:

Hero images
Blog content
High-traffic pages

These deliver the most impact with the least effort.

From there, you can progressively adopt WebP across your entire site.

WebP vs AVIF

You will often hear about AVIF as the next generation format.

It is true that AVIF can produce smaller files than WebP.

However:

Encoding is slower
Tooling is less mature
Browser support, while improving, is not universal

For most teams today:

WebP offers the best balance of performance, compatibility and ease of use.

Make WebP your default

Web performance is not just about complex optimisation. It is about removing unnecessary weight.

WebP does exactly that.

It is widely supported, easy to implement and delivers immediate benefits.

At this point, using JPG or PNG by default is not just outdated. It is inefficient.

WebP is no longer an optimisation tactic. It is the baseline.

Resources

A few useful places to explore if you are ready to start working with WebP:

Official documentation

Tools for creating and converting WebP

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