What happens to a transparent PNG when it becomes an SVG
Nothing about a transparent PNG survives a bad trace quietly. You send in a die-cut sticker, or a mark exported with the checkerboard showing behind it, and the vector comes back sitting on a white tile the size of the original canvas. The sticker cannot be cut to shape, the logo has a rectangle around it on the site, and fixing it means hunting down a shape nobody drew on purpose.
Here the alpha channel is read before any colour is. A pixel whose alpha is above 10 counts as artwork; anything at or below that is marked as lying outside the canvas and is never drawn. No background path is written, no white rectangle hides behind the shapes, and there is nothing to delete afterwards.
What catches people out is the middle of the alpha range. Partly see-through pixels do not stay partly see-through: they are composited onto white before tracing starts, so a shadow sitting at 50% opacity arrives as a solid pale grey shape with a hard edge of its own. That is deliberate rather than an oversight, and much of this page is about living with it.
Drop an image here
or click to choose one
How it works
- Upload the PNG exactly as it is — do not flatten it onto white first. One image per conversion, up to 25 MB and 40 megapixels.
- Set the colour count for the artwork alone, since the transparent area never uses one: 2 for a silhouette, 8 to 12 for a flat sticker or badge.
- Convert, then read the preview knowing it is drawn on white: check the shapes and the edges, ignore the background.
- Sign in with Google (free), download the SVG, and open it over a dark page to see the transparency for yourself.
Who this is for
Three jobs depend on the empty area staying genuinely empty. A cutting machine follows the outermost contour it can find, and a white background rectangle is a contour — the die-cut star becomes a square, blade and all. A website puts the logo on a coloured header, where a white tile shows from across the room. A print job separates the artwork into colours, and an unplanned background becomes an extra separation.
Nothing here removes a background. There is no subject detection; the only thing consulted is the alpha channel already in the file. JPEG cannot carry one at all, so a logo saved as JPEG on white traces that white as a genuine white shape, because that is what it is. WEBP can carry alpha and behaves like PNG. If the background you want gone is painted into the pixels, take it out in an editor first.
One quieter case: a PNG can carry an alpha channel that is opaque everywhere, because exporters add it out of habit. The tracer spots that and stops treating the file as a transparency job at all — a fully opaque RGBA file holds the same picture as a JPEG of it.
Settings we suggest
Colours. Empty canvas is not a colour and never spends one, so every step of the 2 to 64 range goes to the artwork. A single-colour silhouette wants 2; a flat sticker or badge settles between 8 and 12. Remember that a soft shadow, once flattened onto white, claims several of those steps as bands of grey.
Shape stacking. Leave it on Cut-outs. Every colour region is written as a closed shape with the ones above it subtracted, so the hole in a ring and the counter of an O are real holes rather than white patches painted over the top. Stacked writes whole overlapping shapes instead; the transparent surround still holds, but a cutter gets more to untangle.
Draw style. Fill shapes keeps solid artwork solid. Stroke edges keeps the boundaries between regions and drops the fills — and the artwork's border with the empty canvas is one of those boundaries, which makes it the setting for a sticker cut line.
Group by colour puts every path of one colour into its own group, which makes those pale shadow bands easy to select and delete in Inkscape. Emptiness then travels into every format: SVG, PDF and EPS all leave the transparent region undrawn, and the DXF holds outlines only anyway. The PNG output is the vector rasterised again on a transparent background — a tidy raster, not a vector.
Questions
Why does the preview still show a white background?
Because the preview is a PNG, rendered at 800 pixels on the longest side onto a white ground. Transparency cannot be shown there, so a white or very pale design can look like an empty panel while the downloaded SVG is perfectly correct. Judge it by opening the SVG in a browser over a dark page.
What exactly counts as transparent?
The alpha value of each pixel, out of 255. Above 10 is artwork; 10 or below is treated as outside the canvas and left undrawn. So a fully transparent surround disappears, and so does a pixel at roughly 4% opacity you would not have seen anyway. RGBA, greyscale-plus-alpha and palette PNGs are all read this way, as is a WEBP with alpha.
My drop shadow came back as solid grey. Can I keep it translucent?
No. Semi-transparent pixels are composited onto white before tracing, so black at 50% opacity becomes mid grey and is then traced like any other colour. Every path in the output is opaque; nothing in the file is translucent. If the artwork is going onto a dark background, delete the shadow layer before exporting, or group by colour and remove the grey bands later.
Is the transparent edge a real cut line for a die-cut sticker?
Yes. The boundary between artwork and empty canvas is a closed path like any other, which is what a blade or a laser follows. Convert with 2 colours for one clean outline, or choose Stroke edges for contours without fills. The same geometry goes to DXF R2010 (AC1024) for machines that prefer it.
Is it free, and what happens to my upload?
Conversion and preview are free and carry no watermark; a free Google sign-in releases the download files. Signed out you get 10 conversions per hour, signed in 60 per hour and 300 per day. Stickers and logos typically finish in 3-12 seconds in our local measurements; a conversion still running at the 60 second budget stops and suggests fewer colours or a smaller image. Download links expire after 1 hour, and files are cleared by an automatic 1-day deletion rule.