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

The short answer

Use JPEG for photographs that must work everywhere. Use WebP for photographs and graphics on websites when you want smaller files and your audience uses current browsers. Use PNG for screenshots, logos, icons and images with text or transparency when exact edges matter. These rules cover most situations, and the sections below explain the reasons so that you can handle the exceptions.

All three formats are supported by the tool on this page as input. As output, you can keep the original format, or choose JPEG or WebP. PNG files that are kept as PNG often do not get smaller at all, because PNG is lossless and the browser simply re-encodes the pixels, so the compressor keeps the original if the result is not smaller; for large savings, resize them or convert them to JPEG or WebP.

JPEG: the universal photo format

JPEG was standardized in 1992 and is supported by every browser, phone, camera, operating system, email program and website. It uses lossy compression that is tuned for photographs: smooth gradients, natural textures and noise. A well-chosen quality setting can make a photo ten times smaller than the raw pixels without an obvious loss.

JPEG has weaknesses. It has no transparency, so a transparent background becomes a solid color, usually white, when converting. It handles sharp edges and small text badly, because artifacts gather around them. And it should not be re-saved many times, since each save adds errors. For photographs on the web it is still a safe default.

PNG: exact pixels and transparency

PNG, introduced in the mid-1990s, is lossless. It keeps every pixel exactly and supports partial transparency, which is why it is the standard for logos, icons, screenshots and interface graphics. Text in a PNG screenshot stays sharp, and flat colors compress well, so these files can be small.

For photographs, PNG is a poor choice. Natural images contain fine variations that lossless compression cannot shrink much, so a photo saved as a PNG is often several times larger than the same photo as a JPEG. If you have a large photo in PNG format, converting it to JPEG or WebP is usually the biggest single saving available.

WebP: smaller files, modern support

WebP was developed by Google and can store lossy images, lossless images and transparency in one format. Google reports that lossy WebP is 25 to 34 percent smaller than comparable JPEG at an equal quality score, that lossless WebP is 26 percent smaller than PNG, and that lossy WebP with transparency can be around three times smaller than PNG. These figures come from Google's own tests, so your results will differ by image.

WebP is supported by Chrome, Firefox, Safari and Edge, so for most websites it is safe today. The remaining issues are older software: some desktop programs, older email clients and some upload forms still do not accept WebP files. If a file must be opened by anyone, anywhere, JPEG remains the safer choice.

Side by side

For a typical photograph, expect the JPEG to be much smaller than the PNG and the WebP to be smaller again than the JPEG at a similar look. For a screenshot of an app or a web page, the PNG may be smaller than a JPEG that is sharp enough to read, and lossless WebP is often smaller than the PNG. For a logo with a transparent background, PNG and WebP both work and JPEG does not.

Compatibility goes the other way: JPEG works everywhere, PNG works nearly everywhere, and WebP works nearly everywhere but not quite. For a site you control, this is rarely a problem. For files that you send to other people or upload to unknown systems, check what the receiver accepts.

What about GIF and AVIF?

GIF is limited to 256 colors per frame and has only on-off transparency. It survives mostly because of simple animations, and even for those, modern video or animated WebP is usually much smaller. This tool does not process GIF files, because drawing them on a canvas would keep only a single frame.

AVIF, based on the AV1 video codec, often gives even smaller files than WebP and is supported by all current major browsers; caniuse reports global support above 95 percent. Encoding it takes more computing power, and not every browser can create AVIF files from a canvas, so this tool offers JPEG and WebP as output formats. The article on modern formats covers AVIF in more detail.

A practical decision guide

Ask three questions. Is it a photograph or a graphic? Photographs go to JPEG or WebP, graphics to PNG or lossless WebP. Does it need transparency? Then PNG or WebP. Who will open it? If you do not know, choose JPEG or PNG; if it is your own website, choose WebP with a JPEG fallback if necessary.

Whatever you pick, compare the actual file sizes. Add a few of your own images to the compressor and try the options: keep the format, then convert to WebP, and look at the before and after sizes in the list. The best format is the one that gives an acceptable look at the smallest size for your audience.