PNG, JPG or WebP: Which Image Format Should You Use?

Choosing the right image format is one of the easiest ways to make a website faster and cleaner, yet it confuses almost everyone. PNG, JPG and WebP each have strengths, and picking the wrong one means either bloated files or ugly artefacts. This guide explains the practical differences and gives you a simple rule for each situation.

Lossy vs lossless: the core idea

Every image format falls into one of two camps. Lossy formats (like JPG) throw away some detail to make files dramatically smaller — you can't get the original back, but at reasonable settings the loss is invisible. Lossless formats (like PNG) keep every pixel exactly, producing larger files but perfect fidelity. WebP is special: it can do both, lossy or lossless, which is why it so often wins.

JPG: photos and complex images

JPG (also written JPEG) is the workhorse for photographs and any image with smooth gradients and lots of colours — sunsets, portraits, product shots. Its lossy compression is extremely efficient on this kind of content, giving small files that still look great. The trade-off: JPG does not support transparency, and at high compression it produces blocky "artefacts" around sharp edges and text. Never save a logo or a screenshot full of text as a heavily compressed JPG.

PNG: transparency, logos and sharp edges

PNG is lossless and supports transparency, which makes it the right choice for logos, icons, diagrams, screenshots and anything with crisp edges or flat colour areas. Text stays razor-sharp and transparent backgrounds are preserved. The downside is file size: a photograph saved as PNG can be several times larger than the same image as JPG, with no visible benefit. Use PNG when you need transparency or perfect edges — not for photos.

WebP: the modern all-rounder

WebP is a newer format developed by Google that supports both lossy and lossless compression and transparency. In practice it produces files roughly 25–35% smaller than JPG or PNG at equivalent quality, which is a big win for page speed. It is supported by every modern browser. For most websites today, WebP is the best default: use lossy WebP where you'd have used JPG, and lossless WebP where you'd have used PNG.

A simple decision rule

• Photograph, no transparency needed? WebP (lossy), or JPG for maximum compatibility.
• Logo, icon, screenshot, or need transparency? WebP (lossless), or PNG for maximum compatibility.
• Need it to work absolutely everywhere, including very old software? Fall back to JPG/PNG.

Don't forget dimensions and compression

Format is only half the story. A huge photo scaled down in the browser still downloads at full size, so resize images to the dimensions they'll actually be shown at. Then compress: even a well-chosen format benefits from a quality pass. You can do both privately in your browser with our image resizer and image compressor, and switch between formats with the image converter — none of your images are uploaded to a server.

What about GIF, SVG and AVIF?

Three other formats come up often enough to be worth knowing. GIF is ancient and limited to 256 colours; its only real remaining use is simple animations, and even there modern video or animated WebP is usually better and smaller. SVG is completely different from the others — it's not a grid of pixels but a set of drawing instructions, so it scales to any size without ever getting blurry. That makes it perfect for logos, icons and simple illustrations, but useless for photographs. AVIF is the newest contender, often even smaller than WebP at the same quality; browser support is now broad, and it's worth testing if squeezing out every kilobyte matters.

Why format choice affects more than size

Getting the format right isn't just about tidy files — it directly affects how fast your pages load, which shapes both the visitor's experience and how search engines judge your site. Large, poorly chosen images are one of the most common reasons pages feel sluggish on phones and slower connections. Serving a right-sized, well-compressed WebP instead of a giant PNG can turn a heavy page into a snappy one, with no visible loss of quality. Format is a small decision with an outsized effect, which is why it's worth a moment's thought for every image you publish.

A practical habit ties all of this together: for every image before you publish it, ask three quick questions — is it the right format for its content, is it resized to the dimensions it will actually display at, and has it been compressed with a sensible quality setting? Those three checks take seconds each and, applied consistently, keep a site fast without any of the images ever looking degraded. It's the difference between a page that loads instantly and one that keeps visitors waiting on a phone.

Key takeaways

• JPG for photos, PNG for transparency and sharp edges, WebP as the modern default that does both.
• Lossy shrinks files by discarding detail; lossless keeps everything but stays larger.
• Always resize to the display size and compress, whatever format you pick.