Image Formats for the Web: JPEG, PNG, WebP, and AVIF

Pick the wrong image format and a page either looks worse than it should or weighs far more than it needs to. The good news is the choice is mostly mechanical once you know what each format is for. This guide compares the four formats you will actually use on the web and gives you a one-line rule to follow. Convert between any of them with the Image Converter, right in your browser.

Lossy vs lossless, and transparency

Two properties separate the formats. The first is whether compression is lossy or lossless. Lossy formats throw away detail the eye is unlikely to miss, getting much smaller files at the cost of some quality; lossless formats keep every pixel exactly. The second is transparency: whether the format can store an alpha channel so parts of the image are see-through. Photographs want lossy compression; logos, screenshots, and anything with sharp edges or transparency often want lossless.

The four formats at a glance

JPEG and PNG are the old guard: supported everywhere, but larger than they need to be. WebP and AVIF are the modern formats that do the same jobs in far fewer bytes, and both can be either lossy or lossless and both support transparency, so each can replace either old format depending on the setting you choose.

How much smaller are the modern formats?

The savings are large enough to matter. At the same visual quality, WebP is typically 25 to 35 percent smaller than JPEG. AVIF goes further, often around half the size of a comparable WebP, which makes an AVIF roughly a quarter to a third the size of the original JPEG. For a page full of images, that is the difference between a fast load and a slow one.

Browser support in 2026

Support is the other half of the decision. WebP is effectively universal now, handled by every current browser. AVIF is widely supported and still climbing, covering most but not quite all of global traffic, which is why it is usually served with a fallback rather than on its own. JPEG and PNG work everywhere.

The rule to follow

If you serve images through a setup that can offer alternatives, the modern best practice is to provide AVIF first, WebP second, and a JPEG or PNG as the final fallback, letting each browser take the best format it understands. The HTML picture element does this for you.

• Photograph, need it to work everywhere with no fallback: JPEG.
• Logo, icon, screenshot, or anything needing transparency: PNG, or WebP lossless.
• Almost anything, if you want one modern format: WebP.
• A big hero or product image where every kilobyte counts: AVIF, with a WebP/JPEG fallback.
• A logo or icon that must stay crisp at any size: SVG (see the SVG vs PNG guide).

Convert without uploading

The Image Converter changes an image between these formats in your browser, so the file is never uploaded to a server. To check exactly which browsers handle a given format, MDN's guide to image file types keeps an up-to-date reference.