WebP vs PNG vs JPG: which image format should you use?

JPG: the everyday photo format

JPG (also written JPEG) uses lossy compression, which means it throws away detail that the eye barely notices to make files much smaller. It is excellent for photographs, with smooth gradients and lots of colours.

Its weaknesses are sharp edges and text, which can show blurry halos, and it has no transparency. Every time you re-save a JPG, it loses a little more quality, so keep an original and export copies.

PNG: sharp graphics and transparency

PNG uses lossless compression, so the image is stored exactly, with no quality loss. It supports transparent backgrounds. This makes it the right choice for logos, icons, screenshots, diagrams and anything with text or flat colours.

The cost is file size. A photo saved as PNG is usually several times larger than the same photo as JPG, so PNG is a poor choice for photographs on web pages.

WebP: smaller files from one format

WebP was created to replace both of the above. It can be lossy like JPG or lossless like PNG, and it supports transparency. At similar visual quality, WebP files are typically around a quarter to a third smaller than JPG, according to the figures published by its developer, Google.

For websites this means faster loading with less data. All current major browsers display WebP.

The compatibility catch

WebP is not accepted everywhere. Some older software, email programs, print services and upload forms reject it. If you save an image from a website and it will not open or upload, it is probably a WebP file.

In that case, convert it. The WebP to JPG converter makes a widely supported photo file, and the WebP to PNG converter keeps transparency and sharp detail.

Which one should you pick?

• Photographs for sharing, email or uploads to strict forms: JPG.
• Logos, icons, screenshots, text and images that need a transparent background: PNG.
• Images for your own website where speed matters: WebP, with a JPG or PNG fallback if you support very old software.
• Images you plan to edit again and again: keep the original, ideally PNG or the camera file, and export copies.

How to convert between them

1. Open the converter for the pair you need, such as JPG to WebP or PNG to WebP.
2. Drop your image onto the page. It is processed in your browser and is not uploaded.
3. Choose the quality if the tool offers it. Around 80 to 90 is a sensible balance for photos.
4. Download the converted file and check it looks right.

Converting does not add quality

Converting a low-quality JPG to PNG makes the file bigger, but it cannot bring back detail that was already lost. Converting between lossy formats loses a little more each time. Always convert from the best original you have.

If a file is simply too big, the image compressor reduces its size by lowering quality slightly or shrinking the dimensions, which often helps more than changing the format.