What you should know
PNG (Portable Network Graphics) was created in 1996 to replace GIF, then covered by a patent. It compresses losslessly and supports alpha-channel transparency, which makes it essential for interfaces, logos and screenshots.
A PNG keeps every pixel exactly as recorded. That fidelity has a price: the file is often several times heavier than an equivalent JPEG.
Strengths
- Lossless compression: no degradation, even after repeated saves
- Fine transparency through the alpha channel
- Sharp rendering of flat areas, text and lines
- Free format, read everywhere, including browsers
Limitations to know
- Heavy files for photographs
- No animation support (aside from APNG, rarely used)
- Unsuitable for emailing large numbers of images
- Limited EXIF metadata support
When to use it
Use PNG for a logo, an icon, a screenshot with transparency or a flat-colour graphic. For a photo meant for the web or print, convert to JPEG or WebP: the size saving is considerable for a difference that is often invisible.
Quality, size and compatibility
Converting PNG to JPEG is a lossy step: set quality high enough (85–90%) and check edges and dark areas. Lossless PNG to WebP keeps quality intact and already cuts the file by roughly a quarter.
Frequently asked questions
- PNG or JPEG for a screenshot?
- PNG, without hesitation: text and interfaces stay sharp, and transparency is preserved. JPEG introduces halos around letters.
- Why is my PNG heavier than the original?
- A PNG re-saved from an already compressed source recovers nothing and may even grow. Always start from the best available source.