PNG and JPG are the two most common image formats, and they are built for different jobs. JPG makes photographs small by discarding detail the eye barely notices. PNG keeps every pixel exactly and can store transparency, which makes it the format for graphics, screenshots, logos and cutouts. The right choice depends on what is in the picture and where it is going.
The short answer
| JPG (JPEG) | PNG | WebP | |
|---|---|---|---|
| Compression | Lossy | Lossless | Lossy or lossless |
| Transparency | No | Yes | Yes |
| Best for | Photos | Graphics, screenshots, text, cutouts | Websites |
| File size for photos | Small | Large | Smallest |
Pick JPG for photos you want to share, upload or email. Pick PNG for anything with sharp edges or text, anything you will keep editing, and anything that needs a transparent background. Pick WebP for images on your own website.
What PNG is
PNG stands for Portable Network Graphics. The W3C, which approved its first specification in 1996, describes it as a format for "lossless, portable, well-compressed storage" of images, with an optional alpha channel. PNG was designed as a patent-free replacement for GIF.
Lossless means that saving a PNG never changes the picture: open it, save it, and every pixel is identical. That is why PNG suits images you will edit several times. The alpha channel stores how transparent each pixel is, from fully see-through to solid, so a cutout keeps soft, clean edges on any background.
What JPG is, and JPG vs JPEG
JPEG is named after the Joint Photographic Experts Group, which published the standard in 1992. Files usually end in .jpg or .jpeg; the two endings mean exactly the same format. A file ending in .jfif is a JPEG too, and JFIF to PNG covers what to do when an app refuses one. JPEG is also the most common format used by digital cameras.
JPEG compression is lossy and adjustable. At a high quality setting, a photo looks the same as the original while taking a fraction of the space; at a low setting, the file shrinks further and blocky artifacts appear. Each time a JPG is edited and saved again, it is compressed again and loses a little more, so the usual advice is to edit in a lossless format and save a JPG only for the final copy.
Photos: JPG is usually right
For photographs, JPG produces a much smaller file than PNG with no visible difference at good quality. Saving a photo as PNG instead of a high-quality JPG makes the file far larger for a negligible gain in quality. The same phone photo can be several times larger as a PNG.
Graphics, screenshots and text: PNG is usually right
Images with sharp transitions and flat areas of color, such as screenshots, charts, logos, diagrams and anything with text, compress better as PNG than as JPG. They also look better: JPEG compression smudges hard edges and leaves visible artifacts around letters and lines. A Mac saves screenshots as PNG in its standard capture format for this reason.
Transparency: PNG or WebP, never JPG
JPG cannot store transparency at all. A logo or cutout saved as JPG gets a solid background, usually white, wherever it was transparent. To keep a transparent background, save as PNG or WebP. The background remover downloads PNG by default for this reason, and what a transparent background is explains how to spot a fake one.
What converting can and cannot do
Converting between formats changes how the picture is stored, not what it contains:
- JPG to PNG keeps the photo exactly as it is and makes the file larger. It does not bring back detail that JPEG compression removed. It is useful when an app requires PNG or when you want to edit without further loss. Use JPG to PNG.
- PNG to JPG makes the file smaller and flattens any transparency onto a solid color. It is useful for photos saved as PNG by mistake and for upload forms with size limits. Use PNG to JPG.
- WebP to PNG or JPG helps when a picture saved from a website opens in fewer apps. Use WebP to PNG.
All three converters run in your browser, so the images are never uploaded. To shrink a file for an upload form without changing its format, the image compressor can aim for a maximum size in KB.
Where WebP fits
WebP, which Google announced in 2010, supports both lossy and lossless compression as well as transparency. Google reports that lossless WebP images are 26% smaller than PNGs and lossy WebP images 25–34% smaller than comparable JPEGs. All major browsers display WebP, which makes it a strong choice for websites. Outside the browser, some older apps and many upload forms still expect JPG or PNG, which is when converting a WebP makes sense.
Frequently asked questions
What does PNG stand for?
Portable Network Graphics. The W3C specification describes it as a format for the lossless, portable, well-compressed storage of raster images, with an optional alpha channel for transparency.
Is JPG the same as JPEG?
Yes. JPEG is the format, named after the Joint Photographic Experts Group, and its files usually end in either .jpg or .jpeg. The two endings are interchangeable.
Which has better quality, PNG or JPG?
PNG is lossless, so it keeps every pixel exactly. JPG discards some detail to make the file smaller; at high quality settings the loss is hard to see in photos, but it shows around sharp edges and text.
Does converting a JPG to PNG improve its quality?
No. Converting keeps the picture exactly as it is, including any detail the JPG compression already removed, and the PNG is usually a much larger file. Convert when you need PNG for editing or transparency, not to restore quality.
Which format supports a transparent background?
PNG and WebP do; JPG does not. A cutout saved as JPG gets a solid color, usually white, where the transparent areas were.
Should I use WebP instead?
For websites, often yes. Google reports that lossless WebP images are 26% smaller than PNGs and lossy WebP images 25–34% smaller than comparable JPEGs, and all major browsers support it. Some older apps and upload forms still accept only JPG or PNG.