Quick answer

Keep PNG or WebP when transparency is required. JPEG cannot store transparency, so transparent pixels must be filled with white, black or another chosen color.

01

Transparency is stored information

A transparent PNG does not contain a white background. It stores an alpha value for each pixel, and the app’s own background shows through.

A dark viewer can therefore make transparent areas look black even when the file is still correct. Test it over a white background.

02

JPEG removes transparency

JPEG has no transparency channel. Converting from PNG requires the empty area to be filled with a color, which explains many unexpected black backgrounds.

Use PNG for logos, cut-outs and overlays. Use JPEG or WebP for ordinary photographs where transparency is not needed.

03

Match the format to the destination

PNG offers broad support for transparent graphics; WebP may be smaller for the web. Older software and submission systems may not accept WebP.

  • Transparency: PNG or WebP
  • Lightweight photos: JPEG or WebP
  • Maximum compatibility: JPEG or PNG
04

Check edges after conversion

View the result on both light and dark backgrounds. Zoom in around cut-out subjects to catch unwanted dark or pale fringes.

CHECK

After conversion

  • Decided whether transparency is needed
  • Chosen a supported format
  • Tested on light and dark backgrounds
  • Kept the source PNG
Solve it with this tool

Image Converter

Convert JPEG, PNG and WebP while controlling how transparent areas are handled.

Image Converter

This article gives general guidance. If a recipient, printer or official service provides its own requirements, follow those requirements first.

A SMALL NOTE FROM SPACE

Transparency is not nothing; it is carefully stored information. Choose a format that can carry it through space.