WebP vs JPEG vs PNG: Which Image Format Should You Actually Use?

Updated 2026-08-01 · 6 min read

Choosing an image format sounds like a technical detail, but it is usually the single biggest factor in how fast your page loads. Pick badly and a photo that should weigh 80 KB arrives as 2 MB. Here is how the three formats actually differ, and a simple rule for each situation.

The one distinction that matters: lossy vs lossless

Every other difference follows from this. Lossy compression (JPEG, and WebP in its usual mode) permanently throws away visual detail your eye is unlikely to miss. Each time you re-save, more detail disappears. Lossless compression (PNG, and WebP in lossless mode) stores every pixel exactly, so the file survives unlimited re-saves unchanged.

This is why a photograph saved as PNG can be ten times larger than the same photograph as JPEG. PNG is not doing a bad job; it is doing a different job. It is faithfully recording the noise and subtle gradients in a photo that JPEG is designed to discard.

JPEG

JPEG has been the default photographic format since the early 1990s, and its universality is its real strength. Every browser, phone, printer, and ancient piece of software opens a JPEG without complaint.

It compresses photographs extremely well because its algorithm assumes the image contains smooth gradients and gradual colour transitions, which is exactly what a camera produces. Its weaknesses appear when that assumption breaks. Sharp edges, particularly text and line art, develop visible smudging around them, often called ringing or mosquito noise. JPEG also has no transparency at all: there is no way to make part of a JPEG see-through.

Use JPEG for: photographs, especially where maximum compatibility matters, such as email attachments or files someone will open in unknown software.

PNG

PNG was designed for exactly what JPEG is bad at: flat colours, sharp edges, and transparency. A screenshot of an interface, a logo, a chart, or a diagram will look crisp as PNG and slightly mushy as JPEG.

PNG also supports an alpha channel, meaning each pixel can be partially transparent. That is what lets a logo sit cleanly over any background colour instead of arriving in a white box.

The cost is size. Because PNG records every pixel exactly, a detailed photograph becomes enormous. If you have ever compressed a photo and watched the file get bigger, you almost certainly converted it to PNG.

Use PNG for: logos, icons, screenshots, diagrams, and anything needing transparency.

WebP

WebP is the modern option, and it is unusual in that it does both jobs. It has a lossy mode that typically produces files 25 to 35 percent smaller than a JPEG of comparable visual quality, and a lossless mode that usually beats PNG. Crucially, unlike JPEG, WebP supports transparency in both modes.

Browser support is no longer a real concern. Every current version of Chrome, Firefox, Safari, and Edge handles WebP. The remaining friction is outside the browser: some older desktop software, a few email clients, and certain print workflows still do not recognise it.

Use WebP for: almost all images on a website, which is the situation most people are in.

A simple decision rule

• Image going on a web page, and you control the page? WebP.
• Needs transparency and must work everywhere? PNG.
• Photograph someone will download, email, or open in unknown software? JPEG.
• Logo, screenshot, chart, or anything with text in it? PNG, or lossless WebP if it stays on the web.

Three mistakes worth avoiding

Re-saving JPEGs repeatedly. Every save discards more detail, and the loss compounds. Editing the same JPEG ten times leaves visible artefacts. Keep an original in a lossless format and export copies from it.

Using PNG for photographs. This is the most common cause of a needlessly heavy page. If the image came from a camera, PNG is almost never right.

Chasing 100 percent quality. The difference between quality 80 and quality 100 is usually invisible on screen, while the file can easily double. Start around 80 and lower it until you can actually see a problem.

One thing compression cannot undo

Reducing an image's dimensions permanently discards pixels. If you shrink a 4000-pixel-wide photo to 800 pixels and later need it large again, enlarging the small copy will look soft and blurry: the detail is genuinely gone. Always keep your originals and treat compressed versions as disposable exports.