WebP and AVIF are modern image formats that compress photos and graphics far better than JPEG or PNG. WebP offers strong compression with near-universal browser support, while AVIF compresses even smaller at the same quality but encodes more slowly. For most websites, serving AVIF with a WebP fallback delivers the smallest files and the widest reach.
Image weight is usually the largest single contributor to page size, which means image format is one of the highest-leverage performance decisions you can make. Choosing the right format, or letting your platform choose it for you, can cut image payloads by half or more without any visible loss in quality.
This guide compares WebP and AVIF on compression, quality, browser support, and encoding speed, then explains how to use them in practice.
Key takeaways
- WebP typically reduces file size by 25 to 35 percent versus JPEG at comparable quality.
- AVIF usually compresses 20 to 30 percent smaller than WebP at the same visual quality.
- WebP has near-universal browser support; AVIF support is strong in current browsers but slightly behind.
- AVIF encodes more slowly than WebP, which matters for sites generating images on the fly.
- The best practice is to serve AVIF first with a WebP fallback, and let the browser pick what it supports.
Why Image Format Matters for Performance
Images are the heaviest assets on most pages. A single uncompressed hero photo can outweigh all the HTML, CSS, and JavaScript combined. Because images often sit above the fold, their download time directly affects how fast the main content appears, which is measured by Largest Contentful Paint.
Smaller image files load faster, consume less bandwidth, and reduce the work the browser does to decode them. That is why image format shows up in nearly every performance audit, and why it is a recurring theme in the broader work of meeting the Core Web Vitals thresholds. Compressing images well is one of the most reliable speed wins available.
WebP: The Reliable Modern Default
WebP was developed by Google and has been widely supported since the late 2010s. It handles both lossy and lossless compression, supports transparency like PNG, and supports animation like GIF, all in one format. Its compression sits clearly ahead of the older formats it replaces.
WebP strengths
- Near-universal support: Every current major browser renders WebP, so you can often serve it without a fallback.
- Strong compression: Files run roughly 25 to 35 percent smaller than equivalent JPEGs.
- Fast encoding: WebP encodes quickly, which suits dynamic image generation and large batches.
- One format for many jobs: Transparency and animation are built in, reducing the need for PNG and GIF.
AVIF: The Smaller, Newer Contender
AVIF is based on the AV1 video codec and is the newer of the two formats. It pushes compression further, producing noticeably smaller files at the same perceived quality, and it handles wide color gamut and high dynamic range better than WebP. For large photographic images, AVIF’s advantage is most pronounced.
AVIF trade-offs
AVIF’s compression comes at a cost in encoding time. Generating an AVIF file takes longer than generating a WebP file, sometimes significantly so. For a site that pre-generates images at build time, this is a one-time cost and rarely a concern. For a site encoding images on demand for every request, the slower encoding can become a bottleneck. Browser support, while strong in current versions, also trails WebP by a small margin, which is why a fallback remains important.
WebP vs AVIF: Side by Side
The table below summarizes the practical differences that drive a format decision.
| Dimension | WebP | AVIF |
|---|---|---|
| Compression versus JPEG | About 25 to 35 percent smaller | About 50 percent smaller |
| Compression versus the other | Baseline | About 20 to 30 percent smaller than WebP |
| Browser support | Near-universal | Strong in current browsers, slightly behind WebP |
| Encoding speed | Fast | Slower |
| Transparency | Yes | Yes |
| Animation | Yes | Yes |
| Best use | Universal fallback, dynamic generation | Maximum compression for static assets |
How to Serve Both Formats
You do not have to choose one format for the whole site. The HTML picture element lets you offer multiple sources and have the browser pick the first one it supports. Order matters: list AVIF first, WebP second, and a JPEG or PNG last as the universal fallback. The browser walks the list top to bottom and uses the first format it can render.
- Generate all three versions. Produce AVIF, WebP, and a legacy fallback of each important image.
- Use the picture element. List source elements for AVIF and WebP, with an img element holding the fallback.
- Set width and height. Always declare dimensions so the browser reserves space and avoids layout shift.
- Add responsive sizes. Provide multiple resolutions so each device downloads an appropriately sized image.
- Lazy load below the fold. Defer offscreen images so they do not compete with above-the-fold content.
Don’t forget alt text and accessibility
Modern formats change how an image is delivered, not what it communicates. Every meaningful image still needs descriptive alt text for screen readers and for cases where the image fails to load. Treat format optimization and accessibility as parallel requirements, not competing ones.
How Framer Handles Image Formats
On hand-built sites, generating AVIF and WebP versions, wiring up picture elements, and producing responsive sizes is real work that has to be maintained as the site grows. Framer removes that burden by handling image optimization at the platform level. When you upload an image, Framer serves modern formats and appropriately sized variants automatically, choosing the best option each browser supports.
This means a Framer site gets the compression benefits of WebP and AVIF without anyone manually exporting multiple formats or writing markup for fallbacks. The platform also serves images from a content delivery network, so they load quickly worldwide. The result is the kind of clean, fast delivery that supports strong Core Web Vitals, a relationship explored further in the connection between Core Web Vitals and SEO.
What you still control
Even with automatic optimization, the source image quality and dimensions you upload matter. Uploading a needlessly enormous original wastes bandwidth before optimization can help, and an image with poor contrast or composition will not improve through compression. The same attention to visual fundamentals that informs good color contrast choices should guide which images you select in the first place.
Real-World Compression: What the Numbers Look Like
Abstract percentages are useful, but concrete figures make the decision clearer. Consider a typical full-width hero photograph at a resolution suitable for desktop displays. Exported as a quality JPEG, that image might land around 400 kilobytes. The same image as WebP at visually equivalent quality often drops to roughly 270 kilobytes. As AVIF, it can fall to around 200 kilobytes or lower while looking the same to the eye.
Multiply that saving across every image on a page, then across every page of a site, and the bandwidth difference becomes substantial. For a content-heavy page with a dozen images, moving from JPEG to AVIF can shave well over a megabyte from the total payload. On a mobile connection, that translates directly into a faster, cheaper load.
Where the savings matter most
- Photographic content: Both formats shine on photographs with smooth gradients and complex detail, which is where older formats struggle.
- Hero and above-the-fold images: Compression here directly improves Largest Contentful Paint, the metric most tied to perceived load speed.
- Image galleries and grids: Pages with many images compound the per-image saving into a large total reduction.
- Mobile-first audiences: Visitors on metered or slow connections feel the smaller payloads the most.
How Image Format Connects to Other Performance Work
Choosing a modern image format is one of several decisions that determine how fast a page loads, and it works best alongside the others. Lazy loading defers offscreen images so they never compete with the first paint. Declaring image dimensions prevents layout shift as images arrive. Serving from a content delivery network shortens the distance each file travels. Format optimization makes each of those files smaller to begin with.
The underlying network setup matters too. The time to resolve a domain and open a connection happens before any image can download, which is why broader infrastructure choices, including how you handle records covered in the DNS guide for web designers, contribute to the same goal of a quick first render. Image format is the highest-leverage single change, but it sits inside a system, and the system is what determines the visitor’s experience.
Pairing format work with layout fundamentals
Smaller images free up budget for the parts of a page that earn attention. A clean structure built on solid grid systems places those optimized images where they support the message rather than crowd it, and considered microinteractions guide the eye once the page has painted. Performance and design reinforce each other: a fast page that is also well composed holds visitors far better than either quality alone.
Which Format Should You Use?
For most sites, the answer is both. Serve AVIF to browsers that support it for the smallest files, fall back to WebP for the rest, and keep a JPEG or PNG for the rare case neither is available. If you are choosing a single format for a constraint like a simple static setup, WebP is the safer pick because of its broader support and faster encoding. If you are optimizing static marketing assets where every kilobyte counts and encoding time is not a concern, AVIF wins on raw compression. On a managed platform, this decision is made for you on every request.
Frequently Asked Questions
Is AVIF better than WebP?
AVIF generally produces smaller files than WebP at the same visual quality, often 20 to 30 percent smaller, and handles wide color and high dynamic range better. However, WebP encodes faster and has slightly broader browser support. AVIF is better for maximum compression of static assets, while WebP is the more universal choice, which is why serving both with AVIF first is the common recommendation.
Do all browsers support WebP and AVIF?
WebP is supported by every current major browser, so it can usually be served without a fallback. AVIF support is strong in current browser versions but trails WebP slightly, particularly on older devices. Using the HTML picture element to offer AVIF, then WebP, then a JPEG or PNG fallback ensures every visitor receives an image their browser can display.
Does Framer convert images to WebP and AVIF automatically?
Yes. Framer optimizes images at the platform level, serving modern formats and appropriately sized variants automatically based on what each browser supports, and delivering them through a content delivery network. Framer site owners get the compression benefits of WebP and AVIF without exporting multiple formats or writing fallback markup by hand.
If heavy images are slowing your site down, Framer Websites builds fast sites where image optimization is handled automatically on every page. Get in touch through our contact page to discuss your project.