Images

JPG vs PNG vs WEBP vs AVIF: Which Format Should You Use?

How the major image formats actually differ, which one to pick for photos, logos, screenshots and uploads, and the compatibility traps that catch people out.

9 min read · Updated 2026-07-05

Most format advice reduces to "use JPEG for photos and PNG for graphics", which is correct as far as it goes and useless the moment you hit a real decision — a logo with a photograph in it, a screenshot containing a face, a form that will only accept one format. Understanding *why* the rule exists lets you handle the cases it does not cover.

The one distinction that matters: lossy vs lossless

Every format below is either lossy or lossless, and that single property drives everything else.

• Lossless formats reconstruct the original pixel-for-pixel. They compress by finding repetition — a run of 400 identical white pixels stores as "400 white". Brilliant on flat colour, useless on photographic noise.
• Lossy formats discard information the eye is unlikely to notice, particularly fine detail and precise colour. They achieve far smaller files on photographs, and the loss accumulates every time you re-save.

So the question "which format" is largely the question "does my image have flat areas and hard edges, or continuous tone and noise?" Screenshots, logos, diagrams and line art are the former. Photographs are the latter.

The formats

JPEG

Thirty years old and still the default for photographs, because it is the only format that works absolutely everywhere. Its weaknesses are well known: no transparency, visible artifacts when pushed hard, and generation loss on every re-save. Its strength is that no system on earth will refuse it.

For anything you are uploading to a government portal, exam form or older enterprise system, JPEG is not merely a good choice — it is usually the only accepted one.

PNG

Lossless with a full alpha channel, meaning genuinely smooth transparency rather than the on/off transparency GIF offers. It is the right answer for screenshots, UI mockups, diagrams, logos on transparent backgrounds, and any image you plan to edit repeatedly — because re-saving costs nothing.

It is the wrong answer for photographs, where it commonly produces files ten times larger than JPEG for no visible gain. A great many "why is my file so big" problems are simply a photograph saved as PNG.

WEBP

Google's format, now supported by every current browser. It offers both lossy and lossless modes plus transparency and animation, and typically produces files 25–35% smaller than JPEG at equivalent visual quality, or around 25% smaller than PNG in lossless mode.

The catch is outside the browser. Many desktop applications, print services and upload validators still do not accept it. Use it for your own website; do not use it for anything you need to hand to someone else.

AVIF

Based on the AV1 video codec and currently the most efficient widely-available format — often half the size of JPEG at the same quality, with excellent handling of gradients and flat colour where JPEG bands badly. It supports HDR and wide colour gamut.

Browser support is now broad, but encoding is computationally expensive and non-browser support remains patchy. Some browsers can display AVIF but not encode it; where that happens our Image Converter falls back to WEBP rather than failing silently.

SVG

The odd one out: SVG is not pixels at all but a set of drawing instructions. It scales to any size with no quality loss whatsoever, which makes it ideal for logos, icons and diagrams. It cannot represent a photograph in any sensible way. Converting SVG to PNG rasterises it at a fixed size — after which it no longer scales.

Choosing, in practice

Generation loss: the thing that quietly ruins images

Every time a lossy image is decoded and re-encoded, more information is discarded. Save a JPEG ten times at quality 80 and the result is visibly degraded even though you changed nothing. This is why the meme images circulating on WhatsApp look the way they do — each forward re-encodes them.

Practical consequences:

• Keep an original. Always. Edit from it, do not edit the edited version.
• Do all your edits in one session and save once, rather than saving between each change.
• Work in a lossless format while editing if you will make many passes, converting to JPEG only at the end.
• Do not "improve" a JPEG by re-saving at higher quality. You add file size without recovering anything.

Converting between formats

Some conversions are safe and some are not.

• Lossless to lossless (PNG ↔ TIFF): no loss at all.
• Lossless to lossy (PNG → JPEG): loss occurs, but only once, and it is controllable via quality.
• Lossy to lossless (JPEG → PNG): no *new* loss, but the damage already done is baked in — and the file usually gets much larger. Converting a JPEG to PNG does not improve it.
• Lossy to lossy (HEIC → JPEG, JPEG → WEBP): a second round of loss on top of the first. Use a high quality setting to keep it invisible.

Frequently asked questions

Which format has the best quality?

At unlimited file size, the lossless ones — PNG and TIFF — are perfect by definition. At a realistic file size, AVIF gives the best quality per byte, followed by WEBP, then JPEG. The right question is usually "best quality at what size", not "best quality".

Why does my PNG screenshot look better than the JPEG version?

Screenshots are full of hard edges and flat colour — exactly what JPEG handles worst. You are seeing ringing artifacts around the text. Use PNG for screenshots.

Should I switch my website to WEBP or AVIF?

Yes, with a fallback. Both cut image weight substantially, which is the single biggest lever on page load time for most sites. Serve AVIF first, WEBP second, JPEG last using the HTML picture element so older clients still work.

Is WEBP lossy or lossless?

Both — it has two distinct modes. Lossy WEBP competes with JPEG; lossless WEBP competes with PNG and typically beats it by about 25%. Most encoders default to lossy, so check the setting if transparency edges matter.

What about GIF?

GIF is limited to 256 colours and compresses poorly. It survives only because of animation, and even there WEBP, AVIF and short MP4s beat it decisively on both quality and size. For still images there is no reason to choose it.

Can I convert between all of these on this site?

Yes — the Image Converter handles JPG, PNG, WEBP, AVIF, BMP, TIFF, GIF, ICO, SVG input and HEIC input, all processed locally in your browser. AVIF output falls back to WEBP on browsers that cannot encode it.