WebP vs AVIF vs JPEG vs PNG: Which Format When
Four image formats cover practically everything you will publish on the web. They differ in three things that actually matter: how small they compress, whether they keep transparency, and where they open. Everything else is detail.
The one-table answer
| Format | Best for | Transparency | Typical size* | Support |
|---|---|---|---|---|
| JPEG | Photos that must open anywhere | No | 100% | Universal, since 1992 |
| PNG | Screenshots, logos, text, pixel art | Yes | Large for photos | Universal |
| WebP | The modern web default | Yes | ~65–75% | Every current browser |
| AVIF | Smallest files, image-heavy sites | Yes | ~50% | All modern browsers; encoding is slow |
*Rough file size for comparable photo quality, JPEG = 100%.
JPEG: the format that refuses to die
JPEG compresses photographs well and opens on a 20-year-old printer kiosk. It cannot store transparency and it degrades every time you re-save it. Choose it when compatibility beats everything else: email attachments, government upload forms, anything that might meet old software.
PNG: lossless, not “better”
PNG stores pixels exactly. That makes it perfect for screenshots, UI elements, logos and any image with hard edges and text — and terrible for photos, where it can be 5–10× the size of a good JPEG with no visible benefit. If your photo is a PNG, converting it to WebP is usually the single biggest size win available.
WebP: the sensible default
WebP does both jobs: lossy compression that beats JPEG by roughly a quarter to a third, plus optional transparency and lossless modes. Browser support stopped being an argument years ago — every current browser renders it. When in doubt, publish WebP.
AVIF: smallest, with caveats
AVIF (based on the AV1 video codec) produces the smallest files of the four, especially at low bitrates where JPEG falls apart. The costs: encoding is noticeably slower, very old devices skip it, and some tooling still handles it clumsily. For image-heavy pages where bandwidth matters, serve AVIF with a WebP or JPEG fallback via <picture>.
Decision rules
- Photo for the web → WebP (or AVIF with a fallback).
- Screenshot, logo, diagram → PNG; consider lossless WebP for size.
- Needs transparency + small size → WebP.
- Unknown destination software → JPEG.
Ready to switch? Drop your files into the converter — it runs in your browser and nothing gets uploaded. Related reading: how compression actually works and the 3-step size-reduction workflow.