If you’ve spent any time looking into website speed, you’ve probably come across the term “AVIF” and wondered what it actually means. It sounds technical, but the idea behind it is simple: AVIF is a modern way to save images so they take up much less space on disk — without making them look worse.

In this guide, we’ll explain what AVIF is, why it matters for your website, and how you can start using it without becoming an image-compression expert.

What is AVIF?

AVIF stands for AV1 Image File Format. It’s a relatively new image format built on the same underlying video compression technology (AV1) used by streaming services to deliver high-quality video efficiently.

In practical terms, AVIF does the same job as older formats like JPEG, PNG, or WebP — it stores a picture — but it does that job more efficiently. The result is a smaller file that looks just as good, or sometimes better, than the original.

Every image on your website has to travel from your server to your visitor’s browser before it can be seen. Smaller image files mean less data to send, which means the page shows up faster.

Why is AVIF smaller than JPEG or WebP?

AVIF uses more advanced compression techniques than JPEG, which is a format from the early 1990s. JPEG was a great solution for its time, but it simply can’t compress as intelligently as newer formats.

WebP, Google’s format from 2010, was a solid step forward and is still widely used. AVIF goes a step further, typically producing files that are 30–50% smaller than JPEG at the same visual quality. In many cases, AVIF also compresses more efficiently than WebP, especially for photographic images.

What makes this practical rather than just a technical curiosity is that the savings come with no visible loss in quality. A well-encoded AVIF image at a sensible quality setting looks the same to the human eye as its larger JPEG counterpart — it just weighs a fraction of the file size.

Does AVIF support transparency and other advanced features?

Yes. AVIF supports transparency (like PNG), so it can be used for logos, icons, and images that need a see-through background. It also supports a wider color range and HDR (high dynamic range), which can preserve more detail in very bright or very dark areas of a photo.

This means AVIF isn’t a niche format limited to simple photos — it’s flexible enough to replace JPEG, PNG, and in most cases WebP too, across nearly all the images on a typical website.

Do browsers actually support AVIF?

This used to be the main hesitation around adopting AVIF: what’s the point of a great format if browsers can’t display it?

That concern is now largely outdated. All major modern browsers — Chrome, Firefox, Edge, Safari, and Opera — support AVIF today. Because browser support is now so broad, AVIF has moved from “promising new format” to a genuinely safe default for most websites, provided you keep a fallback for the rare older browser that doesn’t support it yet (more on that below).

Why smaller images matter for your website

It’s easy to think of image format as a minor technical detail, but it has real, measurable effects on your site:

• Faster page loads. Smaller files download quicker, especially for visitors on mobile connections or slower Wi-Fi.
• Less bandwidth usage. This matters if you pay for hosting bandwidth, or if your visitors are on limited data plans.
• Better Core Web Vitals. Google’s Core Web Vitals include a metric called LCP (Largest Contentful Paint) — the moment the biggest visible element on the page (often a hero image) finishes loading. Since images are frequently the largest element on a page, shrinking them is one of the most direct ways to improve LCP.
• A smoother experience overall. Pages that load faster feel more trustworthy and professional, which can translate into visitors staying longer and engaging more.

None of this requires visitors to do anything differently. The format change happens behind the scenes; the benefit shows up as a page that simply feels quicker.

How do you actually start using AVIF?

In theory, you could open every image in an editor, export it as AVIF, and re-upload it to your site. In practice, that’s not realistic for a website with dozens, hundreds, or thousands of images — especially if new images get added regularly through blog posts or product listings.

This is where a WordPress plugin that handles the conversion automatically becomes useful. AWP (Accelerate Website Pages) includes an Images module that converts your uploaded images to AVIF automatically, right on your own server, at upload time. Alongside the format conversion, it can also strip unnecessary EXIF data (like camera metadata) and manage maximum image dimensions, so you’re not serving oversized files unnecessarily.

For sites that use AWP’s personalized optimization (via the optional AWP Exchange Server), the process goes a step further. The server looks at how large each image actually needs to be on different devices — phone, tablet, desktop — and AWP then encodes right-sized AVIF variants directly into your own WordPress media library. At serve time, your site delivers the correctly sized AVIF image to each visitor’s device through a responsive srcset, along with a compatible fallback for the small number of visitors on older browsers that don’t yet support AVIF.

Everything happens on your own server and inside your own media library — your images never leave your site as files. It’s a practical way to get the benefits of a next-generation image format without manually converting a single file.

Wrapping up

AVIF is one of the simplest wins available for website performance today: smaller files, no visible quality loss, and support across all major browsers. If your site is still serving JPEG or PNG images by default, switching to AVIF is a low-effort, high-impact change.

If you’d rather not manage the conversion process by hand, AWP’s Images module handles it automatically on your own server, so your images get smaller and your pages get faster without extra manual work on your part.