What is a .png file?
Portable Network Graphics · Image · PNG Development Group / W3C · 1996
PNG is the go-to format for lossless images with transparency: logos, icons, screenshots and web graphics. It never degrades when saved, and it reads on virtually every device, which makes it the safe default when quality matters more than file size.
What is a .png file used for?
PNG uses lossless compression, so re-saving it never adds artefacts. That makes it ideal for text, sharp edges, screenshots and anything with a transparent background.
It supports full alpha transparency and a wide range of colour depths. What it does not do well is photographs, where its files get large compared with JPEG or WebP.
PNG is one of the most universally supported formats in existence, opening in browsers, office apps, editors and operating systems without any plugin.
How to open a .png file
The .png format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list. For a step-by-step walkthrough, see how to open a .png file.
Windows
- Photos
- Paint
- any browser
- any editor
macOS
- Preview
- Photos
- any browser
Linux
- Image Viewer
- GIMP
- any browser
Web
- Every browser
How to convert a .png file
You can convert a .png file to JPG, WebP, AVIF, GIF using a conversion tool or the export menu of an app that opens it.
Convert images free: ImageConvert
.png file signature (magic bytes)
Programs recognise a .png file by the bytes at the start of the file, not by its name. These are the signatures for PNG. For a full breakdown, see the PNG file signature page.
| Hex signature | Offset | Note |
|---|---|---|
| 89 50 4E 47 0D 0A 1A 0A | 0 | PNG signature |
See the full magic-numbers reference for every format.
Frequently asked questions
What is a .png file?
PNG is the go-to format for lossless images with transparency: logos, icons, screenshots and web graphics. It never degrades when saved, and it reads on virtually every device, which makes it the safe default when quality matters more than file size.
When should I use PNG instead of JPG?
Use PNG for logos, icons, screenshots, text and anything needing a transparent background. Use JPG for photographs where smaller files matter.
Why is my PNG so large?
PNG is lossless, so photos with millions of colours produce big files. For photos, JPG, WebP or AVIF will be far smaller.
Comparisons
Related formats
Sources
Details on this page were checked against authoritative references: