New technologies, WordPress ·
AVIF vs WebP: Which Image Format Should Your Site Use?
By Manu Mathew, Technical Lead Engineer · Published 31 October 2026 · Last updated 31 October 2026
A speed test flags your images again, and a plugin offers to convert them to “next-gen formats”. One setting says WebP, another says AVIF. Both promise smaller files, and it isn’t obvious which to pick.
This guide compares AVIF vs WebP in plain terms: what each one is good at, where AVIF still needs care, and how to use either on a WordPress site without breaking how your pages look.
Quick answer
AVIF and WebP are both modern image formats that are much lighter than JPEG and PNG. AVIF usually makes smaller files for the same quality, while WebP is a little more widely supported and quicker to create. For most small business sites, WebP is a safe default, and AVIF is worth adding where your host supports it.
What are AVIF and WebP?
They are newer image formats that store the same picture in fewer bytes than older JPEG and PNG files.
WebP came from Google and has been supported by all major browsers for some time. It handles photos, graphics with transparent backgrounds and simple animations.
AVIF (AV1 Image File Format) is built on AV1, a royalty-free video format. It squeezes images harder, and it can also hold a wider range of colours, including HDR (high dynamic range) photos.
Both can be lossy (dropping detail you’re unlikely to notice to make the file smaller) or lossless (keeping every pixel exactly).
AVIF vs WebP: how do they compare?
AVIF generally wins on file size, and WebP generally wins on support and convenience.
| WebP | AVIF | |
|---|---|---|
| File size | Much smaller than JPEG | Usually smaller than WebP |
| Browser support | All major browsers | All major current browsers |
| Shows while loading | Yes | Only once fully downloaded |
| Wide colour and HDR | No | Yes |
| Time to create | Quick | Slower |
| WordPress support | Built in | Built in since WordPress 6.5, if the server supports it |
MDN, Mozilla’s web documentation, describes lossy AVIF as roughly half the size of a similar JPEG, and notes that AVIF generally compresses better than WebP. You can read the details in MDN’s image format guide.
The real saving on your own site depends on your pictures. Photos often shrink a lot; small icons and simple graphics may barely change.
Which image format is best for a website?
For photos, AVIF or WebP. For logos and icons, SVG where you can. JPEG and PNG mainly as fallbacks.
A simple way to decide:
- Photos and hero images: AVIF if your setup supports it, otherwise WebP.
- Screenshots and graphics with text: lossless WebP or PNG, so sharp edges stay clean.
- Logos and icons: SVG, a vector format that stays crisp at any size.
- Very large, detailed images: test both. AVIF can’t show a partial image while it downloads, so a big file appears all at once.
Most of the benefit comes from switching away from oversized JPEGs and PNGs at all. Choosing between the two modern formats is the smaller decision.
Does WordPress support AVIF?
Yes. Since WordPress 6.5 you can upload and use AVIF images like JPEGs, as long as your server’s image library supports AVIF.
WordPress uses one of two image libraries on the server, Imagick or GD, to create the smaller copies it needs for thumbnails and responsive images. If that library can’t handle AVIF, uploads may fail or the extra sizes may not be created.
You can check this yourself. In the WordPress admin, go to Tools → Site Health → Info, open Media Handling and look for AVIF in the list of supported formats. The WordPress 6.5 AVIF announcement explains this step.
WebP has been supported in WordPress for longer and works on far more servers, which is one reason it remains the easier default.
How do you use AVIF without leaving some visitors behind?
Serve AVIF to browsers that understand it and keep a WebP or JPEG version for anything that doesn’t.
Current browsers handle AVIF, but older phones and outdated browsers may not. There are three common ways to cover them:
- The picture element. The page lists an AVIF version first and a fallback after it, and each browser takes the first one it can show.
- An image plugin or image CDN. A CDN serves files from locations closer to your visitors; an image CDN also picks the right format for each browser.
- Upload AVIF only. Simple, but only sensible if you know almost none of your visitors use older browsers.
WordPress core doesn’t add the fallback for you when you upload an AVIF file. That part usually comes from a plugin, the theme or the CDN, so it’s worth checking which one handles it on your site.
How I approach image formats on a client site
I start by measuring, not by switching formats. On the WordPress sites I work on for small businesses, the steps are usually:
- Find the heavy images. List the largest files on the key pages, such as the home page, services and contact.
- Fix size before format. An image uploaded at four times the width it’s shown at is a bigger problem than its format.
- Check what the server supports. Site Health tells us whether AVIF is an option.
- Pick one approach. Usually one plugin or the CDN, not two tools converting the same images.
- Compare before and after. I check how the pages look on a phone and a laptop, and how page weight changed.
- Write it down. A short note for the owner on what changed, where the originals are, and how to undo it.
Keeping the original uploads matters. WordPress keeps the original file by default, so you can create new sizes or switch formats again later.
Frequently asked questions
Is AVIF better than WebP?
AVIF usually gives smaller files at the same quality and supports a wider range of colours. WebP is quicker to create, shows a partial image while it loads and works on more servers. Neither is better for every image, so many sites use AVIF for photos and keep WebP as a fallback.
Will switching to AVIF or WebP improve SEO?
Not directly, because search engines don’t rank a page higher for using a particular image format. Lighter images can make pages load faster, especially on mobile, which is better for visitors. Fix oversized images and slow hosting first, because format alone won’t make a slow site fast.
Do I need a plugin to use WebP or AVIF in WordPress?
Not to upload them. WordPress accepts WebP files and, since version 6.5, AVIF files where the server supports it. A plugin or image CDN helps when you want existing JPEGs converted automatically, or when you want older browsers to receive a fallback version.
Should I convert all my old images to AVIF?
Only if your server supports AVIF and you have a fallback for older browsers. Back up the site first and keep the original files. Converting the largest images on your most visited pages gives most of the benefit with the least risk, so start there.
Are AVIF and WebP safe to use for a logo?
They work, but SVG is usually a better choice for a logo. SVG is a vector format, so it stays sharp at any size and is often very small. If your logo is only available as a raster image, lossless WebP is a sensible option.
Need help with images on your WordPress site?
Whether your images are slowing the site down or you’re not sure what your setup supports, I’m happy to look at it with you. There’s more about how I help on the WordPress websites page, and why a WordPress site is slow covers the other usual causes.
You can reach me through the contact section or email me at manu@manu.co.in. Tell me a little about your business and the site, and we’ll go from there.