JPG vs PNG vs WebP: Which to Use

JPG, PNG, WebP, and now AVIF — the list of image formats keeps growing, and picking the wrong one means either a blurry photo or a file ten times bigger than it needs to be. The good news is that the choice follows a few simple rules based on what the image actually contains.

The one distinction that decides most of it

Before anything else, ask whether your image is a photograph or a graphic.

• A photograph is made of smooth, continuous gradients — skies, skin, shadows. Millions of subtly different colours, no hard edges.
• A graphic is made of flat colours and sharp edges — logos, icons, screenshots, diagrams, text.

This single distinction points you at the right format, because the formats were designed for different kinds of content.

JPG (JPEG): for photographs

JPG uses lossy compression tuned for photographs. It throws away detail the eye barely notices, achieving small files for complex images. For a holiday photo, JPG at a good quality setting is often five to ten times smaller than a lossless version with no visible difference.

Its weaknesses show on graphics. Put sharp text or a flat logo in a JPG and you get "artefacts" — faint halos and smudges around the edges — because the compression assumes smooth gradients that are not there. JPG also has no transparency: every pixel is opaque.

Use JPG for: photographs, especially where file size matters and transparency is not needed.

PNG: for graphics and transparency

PNG uses lossless compression — it never discards detail, so edges stay razor sharp and the image is pixel-perfect. It also supports transparency, including smooth partial transparency for soft edges and shadows.

The trade-off is size. For a photograph, PNG files are large, because lossless compression cannot do much with millions of colours. But for a logo, icon, screenshot or anything with flat colour and crisp edges, PNG is both smaller and sharper than JPG.

Use PNG for: logos, icons, screenshots, diagrams, line art, and anything that needs transparency.

WebP: the modern all-rounder

WebP, developed by Google, does both jobs. It offers lossy compression that typically beats JPG by 25–35% at the same quality, and lossless compression that beats PNG — while also supporting transparency and animation. In other words, it is usually a smaller JPG and a smaller PNG in one format.

The only real catch used to be browser support, but WebP is now supported by every major browser. For images you control on your own website, WebP is often the best default. The main reasons to still reach for JPG or PNG are maximum compatibility with old software, or a workflow (like print) that expects them.

Use WebP for: web images where you want the smallest file at a given quality, for both photos and graphics.

A quick decision guide

• Photograph for the web → WebP, or JPG for maximum compatibility.
• Logo, icon, screenshot, or anything needing transparency → PNG, or WebP to save space.
• Line art or diagrams that must scale to any size → SVG (a vector format, resolution-independent and tiny for flat graphics).
• Delivering to a printer or old software → whatever they ask for, usually JPG or PNG.

Resize before you compress

Whatever the format, the biggest single saving is usually dimensions. A 4,000-pixel-wide photo displayed in a 800-pixel-wide slot is carrying five times more pixels than it will ever show. Resize the image to the size it is actually displayed at before compressing, and the file shrinks dramatically with zero visible loss. Compression quality is the second lever; dimensions are the first.

Converting without losing quality

A few rules when moving between formats:

• Converting lossy to lossy loses a little each time. Re-saving a JPG as a new JPG degrades it slightly. Keep an original (or a lossless PNG) as your master and export copies.
• PNG to JPG discards transparency — the transparent areas become a solid colour, usually white.
• Anything to WebP is generally safe and smaller, but keep the original if you might need the old format later.

The reliable workflow: keep a high-quality master, resize to the dimensions you need, then export to the right format at a quality you have checked by eye. An image converter and a compressor that run in your browser let you do all of this without uploading private photos to a server — which, for personal pictures, is the sensible default.