JPG, PNG, WebP or AVIF: which image format should you actually use?

Most format arguments go in circles because people compare the formats to each other instead of to the job. There are really only two questions, and they decide almost every case: does the image have hard edges or flat colour, and does it need transparency?

The one rule that covers most images

Photographs are made of smooth gradients — skin, sky, blurred backgrounds. Nothing in them is a sharp boundary between two exact colours. That is what JPG-style compression is built for, and it is why a photo saved as JPG at quality 80 looks fine at a fraction of the size.

Screenshots, logos, icons, diagrams and anything with text are the opposite: large areas of one exact colour, separated by hard edges. JPG destroys those. The tell-tale sign is a faint halo of noise around dark text on a light background, sometimes called mosquito noise. Once you have seen it you cannot unsee it.

So: photographs go to a lossy format, graphics with hard edges go to a lossless one. That is the whole rule. Everything below is refinement.

JPG

The oldest of the four and still the safest. Every device, every email client, every ancient piece of software opens a JPG. It is lossy, it has no transparency, and it does badly on text and flat colour.

Use it when maximum compatibility matters more than file size — a photo attached to an email, an image going into a system you do not control, a print workflow that specifies it.

PNG

Lossless, so nothing is thrown away, and it supports full alpha transparency. That combination makes it the correct choice for logos, icons, screenshots, and any image that will sit on top of an unknown background.

The catch is size. A PNG of a photograph is often larger than the original camera file, because lossless compression has almost nothing to exploit in a noisy photographic image. If you are saving photos as PNG "to keep the quality", you are paying several times the bandwidth for a difference nobody can see.

There is one genuinely useful trick: PNG-8. If your image uses fewer than 256 distinct colours — which most flat-design icons and simple logos do — an 8-bit palette PNG can be a fraction of the size of the 24-bit version with zero visible difference, because there was never more colour information to keep.

WebP

WebP is the sensible default for the web in 2026. It does both lossy and lossless, it supports transparency and animation, and it is roughly 25–35% smaller than JPG at equivalent visual quality. Every current browser supports it — Safari has since 2020.

The important thing people miss: lossless WebP also beats PNG, typically by around 25%. So WebP is not just "a better JPG" — it is a better PNG too. If you are choosing one format for a website and do not want to think about it again, this is the one.

AVIF

AVIF compresses harder than everything above — often 50% smaller than JPG at the same perceived quality, and it holds up remarkably well at very low bitrates where JPG has fallen apart into blocks. It handles wide colour gamut and HDR, which the others do not.

Two costs. Encoding is slow — noticeably so on large batches. And while browser support is now broad, tooling support outside browsers still lags: plenty of desktop software, older phones and CMS uploaders will not open an AVIF.

Use AVIF for images you serve from your own site, where you control the delivery. Do not use it for files you hand to somebody else.

A practical decision list

• Photo on your own website → WebP, or AVIF if you serve a fallback.
• Photo going to someone else → JPG.
• Logo, icon or anything needing transparency → PNG, or lossless WebP if it stays on your site.
• Screenshot with text → PNG. Never JPG.
• Simple flat graphic under 256 colours → PNG-8.
• Anything that must scale — logo, icon set → SVG, which is not in this comparison because it is not a pixel format at all. If you have the vector original, use it.

The conversion trap worth knowing

Converting between formats does not recover quality that has already been lost. A JPG saved at quality 50, converted to PNG, is a lossless copy of a damaged image — the artefacts are now permanent and the file is bigger. The same applies to WebP and AVIF.

Always convert from the highest-quality original you have. If the only copy you own is the compressed one, converting it to a "better" format gains you nothing but bytes.

The other direction is fine: taking a large PNG original and producing WebP or AVIF for delivery is exactly the right workflow, because you still have the untouched source to go back to.