What Is a PNG File?

This article describes what PNG files are, why they're preferred over other image formats in certain situations, and which programs can open one or convert one to other image types.

What Is a PNG File?

A PNG file is a Portable Network Graphics file. The format uses lossless compression and is generally considered the replacement to the GIF image format.

However, unlike GIF, PNG files don't support animations. The very similar MNG (Multiple-image Network Graphics) format does, but it has yet to gain the kind of popularity that GIF or PNG files have.

PNG files store graphics on websites. Some operating systems such as macOS and Ubuntu store screenshots in the PNG format by default.

Another use for PNGs occurs when portions of the image need to be transparent, which can be helpful when making illustrations, designing a website, or creating photography. For example, if you have a logo you want to be placed over a photo, it's much easier to "cut" the logo out, leaving transparent pixels around it, so that when it's placed over the other picture, that picture show sthrough the transparency.

How to Open a PNG File

The default photo viewer program in Windows opens PNG files, but there are many other ways to view one.

All web browsers (like Chrome, Firefox, Safari, others) automatically view PNG files that you open from the internet, which means you don't have to download every PNG file you want to look at online. You can also use the web browser to open PNG files from your computer, by using the Ctrl+O keyboard combination to browse for the file.

There are also several standalone file openers, graphic tools, and services that open PNG files. A few popular ones include:

• XnView
• IrfanView
• FastStone Image Viewer
• Google Drive
• Eye of GNOME
• gThumb

To edit PNG files, the XnView program just mentioned can be used, as well as the Microsoft Windows included graphics program called Paint, the Windows 10 Paint 3D tool, the popular GIMP utility, and Adobe Photoshop.

Considering the number of programs that open PNG files and that you likely have at least two installed right now, there's a good chance that the one that's set to open them by default (i.e. when you double-click or double-tap on one) isn't the one you'd like to use.

If you find that to be the case, see How to Change File Associations in Windows tutorial for detailed instructions on how to change that "default" PNG program.

How to Convert a PNG File

Probably every image file converter that you run across converts a PNG file to another format (like JPG, PDF, ICO, GIF, BMP, TIF, etc.). There are several options in our Free Image Converter Software Programs list, including some online options, like FileZigZag, Zamzar, and TinyWow.

Visit Vectorizer to convert a PNG to SVG.

When to Use PNG Files

PNG files are a great format to use but not necessarily in every situation. Sometimes a PNG can be way too large in size and not only use unnecessary disk space or make it harder to email but can also drastically slow down a web page if you're using one there.

Consider if the image quality benefits are enough to sacrifice that space (or slow web page loading, etc.). Because a PNG file doesn't compress the image like other lossy formats such as JPEG do, quality doesn't diminish as much when the image is in the PNG format.

JPEG files are useful when the image is low contrast, but PNGs are better when dealing with sharp contrast like when there are lines or text in the image, as well as large areas of solid color. Screenshots and illustrations, then, are best in PNG format while "real" photos are best as JPEG/JPG.

You might also consider using the PNG format over JPEG when you're dealing with an image that needs to be edited over and over again. For example, since the JPEG format undergoes generation loss, editing and saving the file repeatedly will result in a lower quality image over time. This isn't true for PNG because it uses lossless compression.

More Help With PNG Files

To make the background transparent in a PNG, your options include automated tools like Clipping Magic or the free Remove.bg tool, or nearly any image editing program.

For example, if you have Photoshop, place the image in its own layer, delete the background layer, and then use any tool (e.g., Eraser, Marquee, Lasso) to erase the portions of the image that should be transparent.