WebP vs AVIF: Which Format Should You Use?

So you've heard about WebP and AVIF. Maybe you've seen them mentioned in some optimization guide, or Google PageSpeed Insights keeps nagging you about them. And now you're wondering... which one should I actually use?

Here's the thing: both are really good. Like, genuinely impressive compared to the old JPEG and PNG formats we've been using forever. But they're different enough that choosing between them actually matters.

Let me walk you through this. No jargon overload, just the stuff that actually matters for your website.

What Are These Formats Anyway?

Before we get into the comparison, let's quickly talk about what we're dealing with.

WebP: The Reliable Modern Format

WebP came from Google back in 2010. Yeah, it's been around for a while now. They built it to replace JPEG and PNG, and it does a pretty good job at that.

WebP images are typically 25-34% smaller than JPEGs at equivalent quality, which is... actually kind of huge when you think about it. Same image, same quality, but takes up way less space.

It supports transparency (like PNG), animation (like GIF), and both lossless and lossy compression. Basically, it's like someone took all the best parts of the old formats and smooshed them together.

AVIF: The New Kid (Who's Really Good)

AVIF is newer. It launched in 2019, which in tech years means it's still finding its footing. But don't let that fool you.

AVIF provides file sizes that are 50% smaller than JPEG and 20-30% smaller than WebP. That's not a typo. We're talking about cutting your image sizes in half compared to JPEG.

It's based on the AV1 video codec (hence the name: AV1 Image File Format), and the compression tech behind it is seriously impressive. Plus it supports fancy stuff like HDR and wide color gamuts, if that's your thing.

The Big Question: File Size and Quality

Okay, let's get to what everyone cares about. How much smaller will my images be, and will they still look good?

Compression: AVIF Takes the Crown

In terms of pure compression, AVIF wins. Like, definitively wins.

When compressing images to similar quality, AVIF achieves 20-30% smaller file sizes than WebP. That's on top of both already being way better than JPEG.

Here's a real-world example. Let's say you have a 1MB photo:

• As a WebP: around 650KB (35% smaller)
• As an AVIF: around 450KB (55% smaller)

That's huge. Especially if you're running an image-heavy site like a portfolio or an e-commerce store where you've got hundreds of product photos.

Quality: Both Are Excellent (But Different)

Now, here's where it gets interesting. Both formats preserve quality really well, but they do it differently.

AVIF excels at retaining fine detail and color depth with support for up to 10-12 bit color, making images appear sharper especially for complex photographs. If you've got photos with lots of gradients or subtle color variations, AVIF handles them beautifully.

WebP is no slouch either. It's really good at keeping things smooth and avoiding compression artifacts. Some people find that WebP preserves smooth gradients better and avoids certain artifacts where AVIF might introduce slight blockiness.

Here's my honest take: for most images, you probably won't notice the difference unless you're really looking for it. But when you do notice it, AVIF usually looks a tiny bit better.

Browser Support: The Practical Reality

This is where things get... complicated. And honestly, this is probably the biggest factor in your decision.

WebP: Nearly Everywhere

As of 2025, WebP has 95.29% browser support. That's basically everywhere. Chrome, Firefox, Safari, Edge, even most mobile browsers. Your visitors can see WebP images. Period.

The only real holdouts are some very old browsers and a few niche mobile browsers. But if someone's using a browser from 2015, they've probably got bigger problems than seeing your images.

AVIF: Getting There

AVIF sits at 93.8% browser support right now. That's actually really good for a format that's only been around since 2019.

January 2024 marked one year since all major browsers fully supported AVIF. Chrome, Firefox, Edge, they all support it. Safari got there too (finally).

The catch? Older versions of those browsers don't support AVIF. So if a chunk of your visitors are using older phones or haven't updated their browsers in a while, they won't see AVIF images without a fallback.

Speed: It's Not Just About File Size

Smaller files are great, but how fast do they actually load and display?

Encoding Speed: WebP Wins

WebP takes less time to decode than AVIF. If you're processing images on the fly (like when users upload profile pictures), WebP is faster.

For websites with lots of user-generated content, this matters. You don't want your server struggling to encode images.

Decoding Speed: WebP Again

WebP images load slightly quicker on the client side due to lower CPU overhead, whereas AVIF can take longer to decode.

In practice? On a fast connection, you probably won't notice. On a slower connection or older device, WebP might feel a bit snappier.

When to Use WebP

Choose WebP when you need:

Maximum Compatibility If you've got a global audience or visitors using older devices, WebP is the safer bet. You're giving up some compression efficiency, but you're gaining peace of mind.

Speed Over Size For sites where images need to be processed quickly (think social media platforms or apps with lots of user uploads), WebP's faster encoding is a big plus.

Simpler Graphics Interestingly, WebP performs better than AVIF for simple illustrations and logos. If you're not dealing with complex photos, WebP might actually be the better choice.

You're Playing It Safe Maybe you're working with a client who's risk-averse, or you just want something that's been battle-tested for over a decade. Nothing wrong with that.

When to Use AVIF

Choose AVIF when you want:

Maximum Compression If file size is your top priority (and it should be for most websites), AVIF is the clear winner. Those extra percentage points in compression really add up.

Best Visual Quality Photography sites, portfolios, e-commerce stores with high-quality product images. AVIF's superior color depth and detail preservation make it ideal.

Future-Proofing AVIF is where things are heading. If you're building something new and your analytics show most visitors are on modern browsers, why not use the better format?

HDR and Advanced Features If you're working with HDR images or need wide color gamut support, AVIF is your only real option between these two.

The Smart Approach: Use Both

Here's the thing. You don't actually have to choose.

The best practice is to serve both formats and let the browser pick. It's easier than it sounds:

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

This gives you:

• AVIF for modern browsers (maximum compression)
• WebP for slightly older browsers (great compression)
• JPEG as the ultimate fallback (works everywhere)

The browser automatically picks the first format it can display. Your visitors on Chrome get the tiny AVIF. Someone on an older iPhone gets WebP. That one person still using Internet Explorer 11 (yes, they exist) gets the JPEG.

Real-World Impact: Does This Actually Matter?

Let me be straight with you. Yes, it matters. A lot.

Page load time is one of those things that seems minor until you realize it's affecting everything. Your bounce rate, your SEO rankings, your conversion rate. Google's Core Web Vitals have made image optimization more important than ever.

AVIF's smaller file sizes translate to faster page load times and reduced bandwidth usage, which means better user experience across the board.

Think about it this way: if you've got 50 images on a page, and each one is 30% smaller with AVIF, you're saving massive amounts of data. That's the difference between a page that loads instantly and one that makes people wait. And on mobile? Even more crucial.

How to Actually Use These Formats

ImgTweak makes this whole process pretty straightforward.

Step 1: Upload Your Images Drag and drop your JPEGs or PNGs. Up to 20 at a time.

Step 2: Choose Your Format Select WebP, AVIF, or both. You can experiment to see which works better for your specific images.

Step 3: Adjust Quality This is where you find your sweet spot. For most photos, 75-85% quality works great for both formats. The preview shows you exactly what you're getting.

Step 4: Compare ImgTweak shows you side-by-side comparisons. Original vs compressed. File sizes. Everything.

Step 5: Download Grab your optimized images. No watermarks, no limits.

And remember: all of this happens in your browser. Your images never get uploaded to a server. It's private, it's fast, and it's free.

My Honest Recommendation

If you're starting fresh and want the simplest answer: use AVIF with WebP and JPEG fallbacks.

The recommendation is to use AVIF with a fallback using the picture tag. This gives you the best of everything.

But if you need maximum compatibility right now, or you're dealing with lots of simple graphics, WebP is still an excellent choice. It's not like you're making a bad decision either way.

The real mistake? Still using regular JPEGs and PNGs without any optimization. That's leaving serious performance on the table.

Common Questions (That People Actually Ask)

Will this break my website? Nope. As long as you include proper fallbacks (like in the HTML example above), every visitor sees an image their browser can handle.

Do I need to convert all my existing images? Not all at once, no. Start with your most important pages, your largest images, your most visited content. You'll see the biggest impact there.

What if my CMS doesn't support these formats? Most modern CMSs (WordPress, Shopify, etc.) support both WebP and AVIF now, either natively or through plugins. If yours doesn't, you can still manually convert and upload.

How do I know which format to prioritize? Check your analytics. Look at what browsers your visitors are using. If 95% are on modern browsers, lean heavy into AVIF. If you've got a chunk of older browser traffic, WebP might be safer.

The Bottom Line

Both WebP and AVIF are massive improvements over JPEG and PNG. AVIF is technically superior in compression and quality, but WebP has better compatibility and speed.

The smart move? Use both. Give your visitors the best their browser can handle.

Start optimizing today with ImgTweak. Upload some images, try both formats, see the difference for yourself. Your website will load faster, your visitors will be happier, and you'll wonder why you didn't do this sooner.

Because at the end of the day, this isn't about picking the "perfect" format. It's about making your website faster and better. And both WebP and AVIF do that beautifully.