As you might know, we serve optimized images using the WebP format, which reduces file sizes compared to traditional formats like PNG or JPEG without compromising visual quality. Now, we've taken image optimization a step further by introducing support for the AVIF format, an even more advanced option that delivers superior compression.
Why AVIF?
By enabling AVIF, we can achieve even greater efficiency in image delivery. Since AVIF has a higher compression ratio than WebP, it offers:
- Faster page loads for both users and search engine crawlers
- Improved Core Web Vitals scores, especially for LCP (Largest Contentful Paint)
- Enhanced user experience
In many cases, AVIF can reduce image sizes by 50% to 66%. For instance, an image that was previously 150KB could now be as small as 50KB without sacrificing significant quality. Of course, this depends on the quality preset that your team agreed to before our deployment.
If you have any questions, we have added the following FAQ to address the most common ones.
Is AVIF supported across all major browsers?
According to Can I Use, AVIF is now supported by the overwhelming majority of modern browsers and is considered part of the Baseline feature set. For browsers that do not support AVIF, our platform automatically falls back to using WebP, ensuring consistent image delivery and performance across all devices.
Will AVIF be compatible with all mobile devices and browsers?
In short, almost all, but not every single one.
There are still a small percentage of users who browse the web using:
- Outdated browsers no longer maintained (e.g., Internet Explorer)
- Older mobile devices that can’t be updated (e.g., iPhone 5/5C/5S)
- Niche devices not optimized for web browsing (e.g., Amazon Kindle)
This is a common challenge with most modern web features. For example, WebP, which your RebelMouse-powered site already uses, is also unsupported by a small group of users, but these represent a very minor portion of global traffic.
What happens on browsers that don’t support AVIF?
Modern browsers include a list of supported formats in the Accept header of every HTTP request. If image/avif is listed, our platform will respond with an AVIF version of the image.
If image/avif is not present but image/webp is, we’ll serve the WebP version instead.
This intelligent fallback mechanism ensures your images are always served in the most optimized format supported by the browser.
Do I need to change how I upload images?
No changes required. You can continue uploading images in JPEG, PNG, GIF, or any other standard format. Our platform automatically handles the conversion and delivery in the best format available for each user’s browser.
Will AVIF affect our editorial workflow or image sizes?
Not at all. This enhancement does not impact your editorial workflow or how images are stored in RebelMouse. You’ll continue to upload and manage images in the same way. The difference happens behind the scenes—images are now served in AVIF format for supported browsers, delivering better performance automatically.
Can an AVIF image be heavier than a WebP image?
In rare cases, yes, but generally that is not the case.
- AVIF excels with complex, photographic images, offering significantly better compression and quality at lower presets.
- WebP may outperform AVIF on simpler images like graphics, icons, or UI elements.
Example:
- A complex image in WebP format at 85% quality weighs 300KB
- The same image in AVIF at 60% quality (same visual quality) weighs 171KB — a 43% reduction
- Using AVIF at 85% quality would increase the size to 425KB, which is heavier than WebP but unnecessary since AVIF provides similar visual quality at much lower quality settings.
Conclusion: When AVIF is used with appropriate compression settings, it consistently delivers better results than WebP for the majority of editorial use cases.
If you have any additional questions, reach us at support@rebelmouse.com.
Table of Contents
- Why AVIF?
- Is AVIF supported across all major browsers?
- Will AVIF be compatible with all mobile devices and browsers?
- What happens on browsers that don’t support AVIF?
- Do I need to change how I upload images?
- Will AVIF affect our editorial workflow or image sizes?
- Can an AVIF image be heavier than a WebP image?
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