What Is a Transparent PNG? How to Make Images with a Transparent Background and Save Them Without Mistakes
You paste a logo and a white box is left around it, or you made the background transparent but it comes back once you save. Transparency problems are almost always caused by saving in the wrong format. This guide explains how transparency works, which formats support it, and how to check it.
Transparency relies on a "fourth value"
An ordinary image stores three values for every point (pixel): red, green and blue. An image that supports transparency adds a fourth value for opacity. That is the alpha channel.
- 100% opacity: nothing shows through. The normal parts of the picture
- 0% opacity: fully transparent, the same as nothing being drawn
- In between: semi-transparent, used for soft shadows and glass effects
The key point is that transparent is not "white". White is a color that has been painted in; transparent means there is no color information at all. They look alike so they're easy to confuse, but the difference shows the moment you put the image on a black background. If it stands out as a white box, it isn't transparent.
Transparency support by format
| Format | Transparency | Semi-transparency | Best for |
|---|---|---|---|
| PNG | Yes | Yes | Logos, icons, diagrams. The first choice when you need transparency |
| WebP | Yes | Yes | Websites. Keeps transparency at a smaller size than PNG |
| JPEG | No | No | Photos. Transparency isn't kept; the background gets filled in |
| GIF | Yes (one color only) | No | Simple animations. Edges tend to look jagged |
| SVG | Yes | Yes | Shapes and logos. No loss of quality when enlarged |
GIF's "one color only" means it treats one chosen color as fully transparent. Because it can't do semi-transparency, the edges of text and logos come out jagged. If you're preparing a transparent logo today, choose PNG or WebP.
If you can't decide between PNG and WebP, use WebP for putting images on a website and PNG for sending to other people or pasting into documents. WebP support is widespread, but some software on the receiving end still can't open it.
Converting to JPEG turns the background white
When you convert a transparent PNG to JPEG, the transparent areas always get filled with some color. JPEG has no alpha channel, so it can't store a transparent state. Most tools fill it with white. The Image Format Converter also fills transparent areas with white before converting when you choose JPEG.
- If you paste it into a document with a white background, the white fill doesn't change how it looks
- If you place it over a dark background, a white box remains and stands out
- Logos with semi-transparent shadows can end up with a white fringe at the edges
Converting a JPEG back to PNG doesn't bring the transparency back either, because the white fill is now saved as part of the image. Always keep the original transparent PNG.
How to check that an image is really transparent
On a white screen, transparent and white look the same. Check in one of these ways.
- 1
1. Place it over a dark background
Put a black rectangle in a slide or document and paste the image on top. If a white box appears, it isn't transparent. This is the quickest check.
- 2
2. Check the file format
If the extension is .jpg or .jpeg, there's no transparency in it. Make sure it's .png or .webp.
- 3
3. Open it in an image editor
If the background shows as a checkerboard, it's transparent. If it shows as solid white, white has been painted in.
- 4
4. Zoom in on the edges
Even when the transparency works, the original background color can linger faintly depending on how it was cut out. Zoom in on the outline of text or logos and check for a white or gray fringe.
| Symptom | Cause | Fix |
|---|---|---|
| The background is a white box | It was saved as JPEG | Export again as PNG or WebP from the original |
| A white fringe remains around the outline | Left over from cutting it out of a white background | Shrink the selection edge by 1 px and export again |
| Only part of it won't go transparent | Semi-transparent areas are filled on a separate layer | Delete the background layer in your editor and export again |
| It looks different in different software | The software doesn't support WebP transparency | Provide a PNG for sharing |
Which format to choose for each use
| Use | Recommended format | Why |
|---|---|---|
| Website logo | WebP (with a PNG as well) | Small while keeping transparency; keep a PNG for environments without support |
| Pasting into documents and slides | PNG | Opens reliably in whatever software the recipient uses |
| Social media icon | PNG | Often made opaque when uploaded, but keep the original transparent |
| PNG or the original file | Check it assuming transparent areas will print as white | |
| The photo itself | JPEG or WebP | If you don't need transparency, these are better for file size |
Social media icons need care. Even if you upload a transparent PNG, the service may replace the background with white or black. To keep the outline from disappearing in dark mode, make the design work even with a background color placed behind it. For choosing a format to reduce file size while keeping the background, see also the differences between PNG, JPEG and WebP.
FAQ
- Why does the background turn white when I convert a transparent PNG to JPEG?
- Because JPEG can't store transparency information. When converting, the transparent areas have to be filled with a color, and most tools use white. To reduce file size while keeping transparency, choose WebP instead of JPEG.
- Is transparent different from white?
- Yes. White is a painted color; transparent means there's no color information. On a white screen they look the same, but on a dark background, white remains as a white box. To check, place the image over a black background.
- Should I use PNG or WebP?
- For websites, WebP is smaller and has the advantage. For sending to others or pasting into documents, PNG is the safer choice since some environments may still not open WebP. Both support transparency and semi-transparency, so you hardly need to worry about quality differences.
- Can I make an image transparent again after saving it as JPEG?
- No. The transparent areas have been painted in as a color, and that information is gone. Converting back to PNG leaves them white. The only option is to cut it out again, so always keep the original file with transparency separately.
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