AVIF generally wins on compression and quality, but WebP has far better browser support and is the safer default for most websites. If your audience uses modern browsers and you want the smallest files, choose AVIF; otherwise, stick with WebP. Use Universal Converter to export the same image in both formats and compare the results yourself.
When to Use AVIF
AVIF is the newer format, based on the AV1 video codec. It delivers excellent compression, often 20-30% smaller files than WebP at the same visual quality. That means faster page loads and lower bandwidth costs, especially for photo-heavy sites.
AVIF also supports HDR and wide color gamut, making it a future-proof choice for high-quality imagery. However, browser support is still catching up. As of 2025, all major browsers support AVIF, but older versions (especially Safari before 16) do not. If your audience is tech-savvy and up-to-date, AVIF is a strong pick.
Use AVIF when:
- You need the absolute smallest file size.
- Your visitors use current browsers (Chrome, Firefox, Safari 16+, Edge).
- You’re serving photos or complex images where compression matters most.
- You can provide a WebP or JPEG fallback for older browsers.
When to Use WebP
WebP has been around since 2010 and enjoys near-universal browser support. It’s the safer choice if you can’t control your users’ browsers or if you want to avoid fallback complexity. WebP also supports transparency and animation, making it versatile for logos, icons, and simple graphics.
WebP is easier to implement because it’s supported by every modern browser, including all versions of Safari since 14. If you’re building a public website, WebP is the pragmatic default that guarantees your images display correctly for everyone.
Use WebP when:
- Your audience might use older browsers or Safari versions below 16.
- You need a simple, no-fallback solution.
- You’re working with graphics that have transparency or animation.
- You prioritize compatibility over the smallest file size.
Why Test Locally in Your Browser?
When you compare AVIF and WebP, the most reliable way is to convert the same image and check the output file sizes. Many online conversion sites require uploading your files, which raises privacy concerns and often limits file size or adds watermarks. Alvseike’s Universal Converter runs entirely in your browser — nothing is uploaded, so your images stay private. There’s no file-size cap, and you can convert as many images as you need within your daily allowance (5 exports per day without an account, 15 with a free account).
This local approach also lets you test both formats side by side instantly. You can see exactly how much smaller an AVIF file is compared to WebP for your specific image, without waiting for uploads or worrying about data leaving your device.
Common Mistakes to Avoid
- Assuming AVIF is always better: AVIF’s compression advantage is real, but if your browser support is weak, you’ll need fallbacks, which adds complexity. Weigh the trade-off.
- Ignoring transparency: WebP supports transparency, but AVIF also does, though not in all encoders. Check if your use case needs it and test accordingly.
- Forgetting about animation: WebP supports animation, while AVIF does not (as of now). If you need animated images, WebP is the only choice among these two.
- Using AVIF on older Safari: If a significant part of your audience uses Safari below version 16, AVIF images won’t display. Always check your analytics.
- Not testing with your own images: Compression ratios vary by image content. A logo might compress differently than a photograph. Always run your own test with Universal Converter.
Making the Decision
Start with WebP if you want a safe, universal solution. Switch to AVIF if you’re optimizing for size and your audience is on modern browsers. Many sites use both: AVIF for browsers that support it, with WebP as a fallback. That’s the best of both worlds, and with a local tool like Universal Converter, you can generate both versions in seconds.
Remember, the choice isn’t permanent. You can always convert your images again. The key is to test, measure, and decide based on your specific needs and audience.