JPG vs PNG: What’s the Difference?

JPG and PNG are two of the most common formats for images on computers and the web, and the difference between them comes down to how they store an image. JPG, also written JPEG, uses lossy compression that discards some detail to make files smaller, and it excels at photographs. PNG uses lossless compression that preserves every pixel exactly, and it supports transparency, which makes it well suited to graphics, logos and text. Neither is universally better; each is designed for different kinds of image.

Two ways to compress an image

Raw image data can be very large, so both formats compress it, but they do so on opposite principles. JPG uses lossy compression, meaning it permanently removes information the human eye is less likely to notice, such as subtle variations in colour and fine detail. The result is a much smaller file, at the cost of some fidelity. Because information is thrown away, saving the same JPG repeatedly can gradually degrade it, an effect known as generation loss.

PNG uses lossless compression, which reduces file size without discarding any image data at all. When a PNG is decoded, it reproduces the original pixels exactly, with no degradation no matter how many times it is opened and saved. The trade-off is that lossless compression generally cannot shrink a photograph as much as lossy compression can, so PNG files of complex photos tend to be larger.

JPG: built for photographs

The JPEG standard was created by the Joint Photographic Experts Group, the body from which it takes its name, and it was designed specifically for photographic images. Photographs contain smooth gradients and countless subtle colour changes, exactly the kind of content whose small losses are hard to perceive. JPG can compress such images dramatically while still looking convincing, which is why cameras and photo-sharing services rely on it.

Most JPG tools let you choose a quality level, trading file size against visual fidelity. A high setting keeps images looking sharp but larger; a low setting saves space but can introduce visible flaws, such as blocky patches or halos around sharp edges, called compression artefacts. JPG also does not support transparency, so it is a poor choice for images that need to sit cleanly over a background.

PNG: built for graphics and transparency

PNG, the Portable Network Graphics format, was developed in the 1990s as a free, patent-unencumbered format and is defined in open specifications published by the W3C and the IETF. It is lossless, so it keeps crisp edges and flat areas of colour perfectly intact. This makes it ideal for logos, icons, diagrams, screenshots and any image containing text, where blurry or blocky edges would be obvious and unwelcome.

PNG’s other signature feature is support for transparency through an alpha channel, which records how opaque or see-through each pixel is. This allows an image to have soft, partially transparent edges and to be placed over any background without a visible rectangle around it — essential for graphics used in web design and interfaces. These qualities are why PNG is a staple of the web, alongside the HTML and CSS that arrange and style images on a page.

Choosing between them

The right format depends on the image and its purpose. A few simple guidelines cover most cases:

• Use JPG for photographs and realistic images with lots of colour and gradient, where small quality losses are acceptable in exchange for a much smaller file.
• Use PNG for logos, icons, line art, screenshots and anything containing text or sharp edges, or where you need transparency.
• Consider the context. On the web, smaller files load faster, so JPG often wins for photos, while PNG is chosen where precision or transparency matters more than size.

It is also worth knowing that other formats exist for particular needs. Newer web formats such as WebP and AVIF aim to combine strong compression with features from both, while SVG stores certain graphics as scalable instructions rather than a grid of pixels. But for everyday use, the JPG-versus-PNG choice remains the most common one people face.

The bottom line

JPG and PNG are not rivals so much as tools for different jobs. JPG trades a little fidelity for small files and shines with photographs; PNG keeps images pixel-perfect and handles transparency, making it the natural choice for graphics. Understanding how each compresses an image — one discarding detail, the other preserving it — makes the decision straightforward, and helps explain why the same photograph and the same logo are usually best saved in different formats.