Add a background to a PNG

How to use it#

1. Drop a PNG onto the box above, or click it to choose one.
2. Pick a colour from the presets or the colour square, or click the picture to use one of its own.
3. Or choose a picture to put behind it, and whether it should fill the space or fit inside it.
4. Check the preview, then download it as a PNG or a JPG.

Why a transparent PNG turns black, or disappears#

A PNG can record how see-through each pixel is, which is what lets a logo sit on any background without a white box around it. Anything that cannot store that information has to decide what to put behind it instead, and the decision is not always the one you would make. JPEG has no way to be see-through at all, so the usual result is black.

The same thing happens in slide decks, video editors, printed documents, and older email clients. Filling the background yourself means you make that decision instead of the software, before the file goes anywhere.

When white is the wrong choice#

White is the most common request because it matches paper and matches most documents, but it is only right when whatever the image lands on is also white. A logo flattened onto white and then placed on a light grey slide shows a visible rectangle, and it is more obvious than people expect.

Match the colour to where the image is going rather than to what looks neutral. The colour square takes any value, and clicking the picture takes a colour straight from it, so a background can match the image or the exact tone of the page it will sit on. The preview shows the result at full size before anything is downloaded.

Soft edges keep working#

A well-made cut-out is not simply see-through or not. The pixels around a curve are part way between the subject and whatever is behind them, which is what stops the edge looking jagged, and the same is true of a soft shadow or a faded gradient.

Those pixels are blended with the colour you choose rather than being forced to one side, so a rounded logo stays rounded and a shadow stays soft. The result panel reports how much of the image is only partly see-through, because that is the part where the colour choice shows up most.

Flattening is not reversible#

Once the background is painted in, the file no longer records which pixels used to be see-through. Changing your mind means going back to the original, not undoing it here, so keep the file you started with.

For the same reason, think twice before saving as a JPG. A JPG cannot be see-through under any circumstances, and it re-compresses the image on the way out, so it adds a small loss of quality to a decision that was already permanent. Either way, the file to keep is the transparent one you started from.