Why a transparent PNG turns black or white, and how to keep it
A transparent PNG turns black or white when a program saves it as JPG, or when an app re-encodes it, because JPG has no alpha channel to store transparency. The program has to put a colour behind the transparent pixels. It either paints white or keeps whatever colour values the pixels store, which are often black. Keep the file as PNG or WebP if it must stay transparent, or choose the background yourself before saving as JPG.
Remove backgroundBackground needs to goOpenWhat transparency is in a PNG
A PNG can store an alpha channel alongside the red, green and blue values of each pixel. Alpha records how opaque a pixel is. A fully transparent pixel shows whatever lies behind the image, such as a page colour or a document background. The viewer does the blending, so the same file looks right on a white page and on a dark one.
JPG has no alpha channel. Every pixel is a solid colour, so a transparent area has to be written as some colour, and the format gives the converter no way to keep the idea of see-through.
Why it turns black or white
When a converter drops the alpha channel, it has to decide what each formerly transparent pixel becomes. Two results are common:
- Stored colour. A transparent pixel still has red, green and blue values, and in many cut-outs those values are black. A converter that simply discards alpha keeps those values, so the background looks black.
- A fill colour. Other converters paint a background first, usually white, and draw the image over it. The convert tool does this: saving as JPG fills transparent areas with white, and the tool says so beside its controls.
Apps add a third route. Upload forms, chat apps and email clients often re-encode pictures before showing them, and some convert to JPG on the way. The result depends on the app, so the same PNG can look correct in one place and black in another.
Keep the transparency or choose the background
Decide which of the two outcomes you need:
| You need | Save as | Result |
|---|---|---|
| A cut-out for a website or design | PNG or WebP | Transparency kept |
| The same cut-out on a plain background | JPG | A background colour you chose |
To keep transparency, open the convert tool and pick PNG, or WebP where your browser can save it. Both keep transparent areas. The compress tool keeps transparency too: it saves a transparent image as WebP, or as PNG in browsers that cannot write WebP, such as Safari.
If you need to create the transparency first, use the remove background tool. It runs an AI model in your browser, and the choice at download decides the format:
- Keep it transparent, and the tool saves a PNG.
- Pick white, a colour or a blur, and it saves a JPG with that background.
If a form needs a JPG, choose the background at the cut-out step. Do not leave it to the converter, which may pick black.
Test whether the transparency survived
Open the converted file on two backgrounds before you trust it. Put it on a plain white web page and on a dark one, or place it on a coloured slide or document. If the picture shows the same background on both, the file has no transparency and the colour is baked in. If the surrounding colour changes, the transparency survived.
Editors show transparency differently again. Many image editors draw a grey and white checkerboard behind transparent areas, while plain viewers may show black or white. The checkerboard is the editor's way of showing that nothing is there, not a pattern in the picture. Check the file in the program where it will be used, and treat any other preview as a rough guide.
Choose the fill on purpose
When the output must be a JPG, decide the background before the converter does. White suits a page or document that is white. A solid colour suits a brand block or a coloured page, and it should match the page behind the image so the soft edges blend in. The remove-background tool's blur option fills the background with a soft, blurred copy of the same photo, which can look more natural than a plain fill for a photograph. Pick the option that matches where the picture will sit, and check it there.
Edge cases
- Soft edges. Hair, shadows and glass have partly transparent pixels that still carry the colour of the old background. On a new background a light or dark fringe can appear. Use a cut-out with clean edges, or pick a background colour close to the original.
- JPG cannot keep transparency. If a form accepts only JPG, the transparency must be replaced by a colour. No JPG setting changes that.
- Check on the target. Look at the file where it will be used, such as the form, the page or the app. A preview may use a different background from the real one.
- Choosing a format. For graphics on the web, PNG is the usual choice. JPG, PNG and WebP compares them in more detail.
