Why a JPG cannot be transparent
JPEG stores three channels: red, green and blue. There is no fourth channel for “how much of this pixel is here”, so a JPG with a white background has white pixels where you wanted nothing. A PNG can store that fourth channel, which is why it is the format to save a cutout in — but the channel has to be filled in by removing the background, not by renaming the file.
This page opens on the guided selection with a slightly wider edge band and a softer ramp than the front page, because JPEG compression smears edges. If your JPG is a logo or a product on a flat colour, the colour-key pages are usually better still.
- Detail lost to compression stays lost. Removing the background cannot restore hair or texture that the JPEG encoder threw away.
- The PNG will be larger than the JPG. PNG is lossless, so the same picture takes more bytes. Choose WebP on the Save panel for a smaller file that still keeps transparency.
Questions about JPG to PNG
I converted my JPG to PNG and the background is still there. Why?
Because changing the format does not create transparency. A JPG has no alpha channel, so every pixel of its background is a real colour; a PNG converted from it has the same pixels. The background has to be removed — which is what this page does — and only then does the PNG carry transparency.
Why does the edge look blocky on some JPGs?
Heavy JPEG compression leaves an 8 × 8 pixel grid and halos around sharp edges. When the page detects that grid on open, it starts the edge band 3 pixels wider so the matte rides over the artefacts instead of tracing them, and tells you it did.
My JPG has a plain white or coloured background. Is there a better method?
Yes — the colour key. When the border of your JPG is one flat colour, the Cut panel offers to switch to the key on that colour, which unmixes the edge against it and usually gives cleaner anti-aliasing than the guided selection. Undo brings the other result back so you can compare.
Can I convert a whole folder of JPGs?
Yes. Drop several files at once and they open as a queue, up to twenty-five; each one is cut and saved as a transparent PNG in one ZIP.
Related
- Remove white backgroundA colour key on white with exact unmixing, so anti-aliased edges become soft transparency instead of a grey ring.
- Make a picture transparentThe same studio, with the file-format question answered on the way out.
- Remove background from logoKeyed on the logo's own background colour, trimmed to the artwork, with a square canvas when you need one.
- Why a transparent PNG can still look whiteTransparency is a channel, and every app you paste into decides what sits behind it.






