How to make a transparent PNG
Making one is straightforward. Confirming it worked — and knowing why it sometimes does not — is where people get stuck.
The short version
Four steps
- 1
Cut the subject out
Load your image, mark the subject and run the cutout. What disappears behind the checkerboard is what will be transparent.
- 2
Choose PNG as the export format
PNG stores an alpha channel. Selecting JPEG at this step is the most common way to lose the transparency you just made.
- 3
Decide whether to trim
Trimming crops the empty transparent space, giving a smaller file. Keep the canvas if the subject's position matters.
- 4
Verify over a colour
Place the downloaded PNG on a dark or coloured surface. If the colour shows right up to the subject's edge, the transparency is real.
What the alpha channel does
A PNG stores red, green and blue for every pixel, and optionally a fourth value: alpha. Alpha says how opaque that pixel is, from fully solid to fully invisible.
Values in between are what make a cutout look believable. Where a strand of hair covers half a pixel, that pixel is half transparent, so the subject blends into whatever it is placed on rather than ending in a hard staircase.
Why a preview can lie
Many image viewers render transparency as white. Others render it as a checkerboard. Neither is part of your file, and both make it easy to misjudge what you have.
The reliable test is compositing: drop the PNG onto a strongly coloured background in a document, a design tool or a browser. Anything white that should not be there is instantly obvious.
Common ways transparency gets lost
Exporting as JPEG, which has no alpha channel at all. Saving through an app that flattens layers on export. Pasting into a program that composites onto a white page before saving.
Uploading to a platform that converts images to JPEG on its own is another one worth knowing about — the file you uploaded had transparency, and the version being served no longer does.
PNG file size, briefly
PNG compresses losslessly, which handles flat graphics beautifully and photographs poorly. A photographic cutout can be several megabytes.
Trimming the transparent margin is the easiest reduction. Beyond that, WebP with alpha is typically far smaller and is supported by every current browser.
Frequently asked questions
Is a transparent PNG the same as a white background?
No. Transparent pixels carry no colour and show whatever is behind them. White pixels are white everywhere, including on a dark slide.
Why does my PNG look transparent in one app and white in another?
Because the two apps display transparency differently. Test by placing the file over a coloured background rather than trusting either preview.
Should I use PNG or WebP?
PNG for maximum compatibility and lossless quality. WebP when the file is going on a web page and size matters more than universal support.