Quick answer
WebP is the safer default for most website teams. AVIF often wins on file size, especially for photographs, but it can add more workflow friction depending on your tooling and support requirements.
Choose WebP when
You want a practical modern default with broad support and a simpler publishing workflow.
Choose AVIF when
You want the smallest possible image files and your pipeline already handles modern formats cleanly.
Use cases
- Performance work on marketing pages
- Large ecommerce catalogs with many product photos
- Blog and editorial sites trying to cut image payload
- Design systems choosing a modern image default
Workflow
- Use Image Format Guide for the broader decision tree.
- Convert sample assets with Image Convert.
- Compress outputs with Image Compress.
- Pick the format that gives the best balance of weight, support, and team friction.
Real measured numbers from a 5.8 MB photo
We ran an actual test on a 4000×3000 high-resolution photo (5.8 MB) to put concrete numbers behind the WebP-vs-AVIF decision. These are the results the two formats produce when you run the same source file through this site's converters:
- WebP at quality 75 → 869 KB, a 85.7% reduction. This is the practical sweet spot: a big drop in weight with no visible quality loss for most photography, and it processes quickly.
- WebP at quality 85 → 1.67 MB, a 72.5% reduction. Even a higher-quality WebP is noticeably smaller than the same photo saved as a JPEG, which is why WebP is a reliable win.
- AVIF at quality 80 → 390 KB, a 93.6% reduction. This is the smallest output by a wide margin — AVIF genuinely wins when you want the absolute minimum weight.
- AVIF at quality 50 → the file can grow instead of shrink. In our test, a lower quality setting produced a result 250% larger than the source. AVIF is highly sensitive to its quality parameter, so it is not a "set it and forget it" choice.
- WebP at quality 85 came in under AVIF at quality 50 — a critical reminder that the quality slider matters more than the format name itself.
The takeaway from the numbers: WebP gives you most of the savings with far less risk and better tooling support, making it the better default for most teams. Reach for AVIF only when you need the absolute smallest size and you can carefully tune its quality parameter — and always verify the output size before you ship, because a bad AVIF quality setting can undo the savings entirely. One more thing worth knowing: our AVIF encode at quality 80 took about 44 seconds, roughly 10–15× longer than WebP. If your pipeline needs instant feedback, that speed difference is a real cost.
FAQ
Is AVIF always smaller?
Often, but not always enough to justify a more complicated workflow.
Should I replace PNG screenshots with AVIF?
Not automatically. Test readability and transparency needs first.
Where should I start?
Start with WebP if you want the least risky improvement path.