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JPG, PNG, WebP, AVIF — Which Image Format Should You Use?

A plain-English guide to the formats that matter, when to reach for each, and how to shrink files without wrecking quality.

The format you export decides how sharp your image looks and how fast your page loads. Pick the wrong one and you either get a blurry photo or a file so heavy it slows your whole page down. Here's the plain-English version of what to use, and when.

JPG

Best for photographs. JPG uses "lossy" compression — it throws away detail your eye barely notices to make files small. That's perfect for hero images and photo galleries, where a little compression is invisible. Its one limitation: no transparency, so it always fills the background with a solid colour.

PNG

Lossless with transparency. Reach for PNG with logos, icons, screenshots, and anything with crisp edges or a see-through background. The trade-off is size: a large photo saved as PNG can be several times bigger than the same photo as JPG, so don't use it for photography.

WebP

The modern default. WebP is roughly 25–35% smaller than JPG at the same quality, supports transparency like PNG, and is read by every current browser. If you're publishing to the web and unsure what to pick, export WebP — you get PNG-style features at JPG-style sizes.

AVIF

The newest and smallest format, with excellent quality at very low file sizes. Support is now broad but not quite universal, so for critical images pair it with a WebP or JPG fallback for older clients. For most sites, AVIF is where the biggest speed wins are.

What about HEIC and SVG?

  • HEIC is what modern iPhones save by default. It's efficient but not universally supported on the web, so convert it to JPG or WebP before uploading anywhere.
  • SVG isn't a pixel format at all — it's vector code. Use it for logos and icons that must stay razor-sharp at any size. It can't store photographs.

A simple rule of thumb

  • Photo on the web: WebP (AVIF if you can add a fallback)
  • Logo, icon, transparency: PNG (or SVG for vectors)
  • Maximum compatibility: JPG
  • iPhone photo to share anywhere: convert HEIC → JPG

File size vs quality — the real trick

Format matters, but so does what you do after choosing it. Two quick wins:

  • Resize before you compress. A 4000px photo shrunk to fit an 800px slot is wasted weight. Resize it to the size it'll actually display first.
  • Then compress. Run it through the image compressor and watch the file size drop with no visible loss.

FAQ

Does converting JPG to PNG improve quality? No. Quality lost to JPG compression can't be recovered by switching format — you just get a bigger file. Start from the highest-quality original you have.

Is WebP safe to use everywhere now? Yes, for the web. Every current browser supports it. For email or some older desktop software, JPG or PNG is still the safest bet.

Which format is smallest? AVIF, then WebP, then JPG for photos. For graphics with few colours, PNG or SVG usually wins.

You can convert and compress any of these in the free tools — no upload, everything runs in your browser. Start by converting an image.