PNG and JPG are the two image formats almost every device, program and website understands. They look similar in a file list, but they work in completely different ways. Once you understand the difference, the choice becomes obvious in most cases.
Lossy versus lossless
JPG is lossy. When you save a JPG, the encoder throws away detail that the eye is less likely to notice, such as subtle color variations and tiny texture. The quality setting decides how much is thrown away. At high quality the result is very close to the original, and the file is a fraction of the size of an uncompressed image.
The price is that the discarded information is gone for good. JPG also leaves typical traces when pushed too far: blocky areas in smooth skies, and a halo of noise around sharp edges and text. Every time you open a JPG, edit it and save it again as JPG, a little more is lost.
PNG is lossless. It stores every pixel exactly. When you open a PNG, you get back precisely what was saved, no matter how many times you save it. The compression works by finding repetition, so images with large flat areas and few colors compress very well, while photos with endless subtle variation do not.
Transparency
PNG supports an alpha channel, which means each pixel can be fully transparent, fully opaque or anything in between. That allows smooth edges on a logo placed over any background.
JPG has no transparency at all. When you convert a transparent PNG to JPG, the transparent areas have to be filled with a color. The PNG to JPG converter lets you choose that background color; white is the default.
Which format for which image
| Image type | Better choice | Why |
|---|---|---|
| Photo from a phone or camera | JPG | Much smaller with no visible difference |
| Screenshot with text or interface | PNG | Keeps letters and lines crisp |
| Logo, icon, simple illustration | PNG (or SVG if available) | Flat colors, sharp edges, transparency |
| Product photo with transparent background | PNG | JPG cannot be transparent |
| Photo for an upload form | JPG | Small and accepted almost everywhere |
| Chart or diagram | PNG | Thin lines and text stay sharp |
| Image you will keep editing | PNG while editing | No loss between saves |
Photos
For photos, JPG is the clear winner. A photo saved as PNG is often several times larger than the same photo as a good JPG, and nobody can see the difference at normal viewing size. A quality setting between 80 and 90 suits most uses; the PNG to JPG converter uses 85 by default.
Screenshots, text and graphics
Here the situation reverses. JPG compression struggles with the hard edges of text, thin lines and flat color areas. Letters get a faint fuzzy halo, and solid backgrounds pick up blotches. A PNG keeps them perfectly clean, and because such images contain large uniform areas, the PNG is often small anyway.
When a screenshot PNG is still too large, the PNG compressor can help. It reduces the image to a palette of at most 256 colors (or fewer, if you choose) and saves an 8-bit PNG. Screenshots, logos and illustrations usually look the same afterwards while the file shrinks considerably. Transparency is preserved.
A screenshot that is mostly a photo, such as a screenshot of a picture in your gallery, behaves like a photo, and JPG will usually be smaller.
Why converting JPG to PNG does not improve quality
It is a common idea: PNG is lossless, so converting a JPG to PNG should make it better. It does not. The detail the JPG threw away is not stored anywhere, so the PNG cannot bring it back. What the PNG does is store the JPG, including all its compression artifacts, without any further loss.
The file also grows, often a lot. The artifacts and fine noise of a JPG are exactly the kind of irregular detail that lossless compression handles badly.
There are still good reasons to convert, and the JPG to PNG converter is there for them:
- You are going to edit the image in several steps and do not want each save to add new JPG artifacts.
- A system or program requires PNG.
- You plan to add transparency later, for example to cut out an object.
Color depth in brief
JPG files normally store 8 bits per color channel, which gives about 16.7 million colors. PNG can store an 8-bit palette of up to 256 colors, full 8-bit color with or without transparency, and even 16 bits per channel for special uses. For everyday images these differences rarely matter; the lossy versus lossless question matters far more.
WebP as a modern alternative
WebP combines the strengths of both. It has a lossy mode for photos, a lossless mode for graphics, and supports transparency in both. For photos, a WebP is usually noticeably smaller than a JPG of similar quality. All current major browsers display it, so it is a strong choice for websites.
The limitation is outside the browser: some programs and many official upload forms still accept only JPG and PNG. Use the WebP converter for website images, and keep JPG for anything you send to forms and other people. The WebP vs AVIF guide compares the modern formats in more detail.
A quick decision procedure
- Does the image need transparency? Use PNG (or WebP for a website).
- Is it a photo or photo-like image? Use JPG (or WebP for a website).
- Does it contain text, lines, or flat color areas? Use PNG, then run it through the PNG compressor if it is large.
- Is it going to a form or a program with strict rules? Use whatever format the rules name.
You can read more about each format on the PNG, JPG and WebP format pages.
Frequently asked questions
Is PNG higher quality than JPG?
PNG never loses detail, while JPG does. But a high-quality JPG of a photo looks the same as a PNG to the eye at a fraction of the size. Quality only becomes a visible issue with low JPG settings or with text and graphics.
Can I make a JPG transparent?
No, the format does not support transparency. Convert it to PNG and remove the background in an image editor; the converter alone will not make anything transparent.
Why is my screenshot PNG so large?
Large screens produce screenshots with millions of pixels, and photos or gradients in the screenshot make lossless compression less effective. Reducing colors with the PNG compressor or cropping to the relevant area usually helps a lot.
