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.
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.