Most “which format?” questions come down to two things: is it a photo or a graphic, and does it need transparency?
Image: Animdock Stock — free to download.
JPG — photos, everywhere
JPG compresses photographs very efficiently by throwing away detail the eye barely notices. It has no transparency and gets blocky around sharp text. Use it for photos you share, email or upload anywhere.
PNG — exact pixels and transparency
PNG is lossless: what you save is exactly what you get back, every time. That makes it right for screenshots, logos, UI graphics and anything with a transparent background — at the cost of large files for photos.
WebP — the web all-rounder
WebP does both lossy and lossless compression, supports transparency and is typically 25–35% smaller than JPG or PNG. Every current browser shows it; some older desktop apps still don’t open it.
AVIF — the smallest
AVIF, built on the AV1 video codec, often beats WebP by another 20–30% at the same quality. It is ideal for performance-critical sites; encoding is slower and older software can’t open it yet.
Image: Animdock Stock — free to download.
The short version
| Need | Format |
|---|---|
| Photo to share | JPG |
| Logo, screenshot, transparency | PNG |
| Website images | WebP (or AVIF) |
| Several images as one document |
You can switch between all of them for free with the Image Converter — try PNG to WebP to make a site lighter in minutes.