Guide
Background Remover PNG
Short answer: when the input is already a PNG, the format sets a ceiling on how clean the result can be — before any slider is touched. PNG is lossless, so it never adds noise the way a JPEG does, but its colour type and bit depth decide how much precision the key actually has. A palette PNG cannot express a soft transition at all; a 16-bit PNG carries more steps than the keyer uses; a screenshot can carry a checkerboard as real pixels. Check which PNG you have before you try to improve the edge, because two of those three cannot be fixed in the remover.
Which PNG do you actually have?
| What you have | What it does to a key | What to do |
|---|---|---|
| RGBA or greyscale + alpha, 8-bit or 16-bit | Full per-pixel precision; the edge can carry any transparency | The normal case. Key it and rebuild the edge |
| Palette PNG (indexed colour) | The image holds at most a few hundred distinct colours, and transparency is a single palette entry | Convert to RGBA before keying; otherwise every edge is on or off |
| A screenshot of something transparent | The “empty” area is literal grey and white squares | Go back to the source file. A key cannot separate a painted checkerboard from a real one |
Why the palette case is not a settings problem
An indexed PNG does not store a colour per pixel. It stores a number per pixel and a table of colours, and transparency is itself one of the table entries. That means a pixel is either inside the palette or fully transparent — there is no room in the format for “40 percent covered”.
Keying such a file produces a hard, stepped edge. Raising the edge softness in the remover helps, because the softness is written into the new alpha channel, but the colour data underneath is still quantised. Converting the PNG to RGBA first gives the key real intermediate values to work with, and the result usually looks noticeably cleaner at the same settings.
Why 16-bit does not automatically help
A 16-bit-per-channel PNG stores finer steps than the screen can show, which is useful when you are grading or compositing repeatedly. A keyer, though, makes a decision about colour distance; extra steps mostly reduce banding rather than improve the edge itself. Expect a 16-bit source to be more forgiving of gentle gradients and no better at resolving hair.
The one advantage PNG always has
PNG is lossless and stores full colour at every pixel — no chroma subsampling, no block artefacts. That is why a clean key on a PNG looks cleaner than the same key on a JPEG: there is no compression noise around the boundary for the threshold to latch onto. If you have a choice of source, take the PNG every time; if the only copy is a JPEG, expect to spend more time on the edge.
Checklist before you key
- Look at the file type in your editor’s image information, not just the extension.
- If it says indexed or palette, convert to RGBA and re-save before removing anything.
- If the empty area is a checkerboard pattern of two greys, it is a screenshot; find the original.
- If it already has an alpha channel with holes, you do not need a remover — you need an editor to repair the edge.
Where this tool fits
The remover here accepts a PNG (or any browser-decodable image), keys one colour, and writes an 8-bit RGBA PNG at the size you loaded. It works on the pixels the browser decoded, so a palette PNG is decoded to RGBA before it sees it — which is exactly the conversion described above, done for you.
What it will not do is recover a checkerboard that was captured into the pixels, or invent precision that a heavily quantised file never had. Open the green screen remover for the normal case; this page covers how to tell which kind of “transparent PNG” you were handed.
Questions
Can a PNG have partial transparency?
Yes, if it stores an alpha channel — RGBA or greyscale plus alpha. Palette PNGs are the exception: transparency there is a single palette entry, so pixels are either visible or fully transparent.
Why is my keyed PNG edge jagged?
Most often the source was an indexed PNG, where the format cannot represent in-between values. Convert the file to RGBA first, then key; the same settings will produce a smoother edge.
Does a 16-bit PNG give a better cut-out?
It gives smoother gradients and less banding, but the key still works on colour distance. Expect gentler transitions, not sharper hair.
Is PNG better than JPEG for background removal?
Yes. PNG is lossless, so there is no compression noise around the edge for the threshold to catch. JPEG artefacts are one of the most common reasons a key looks ragged.
My PNG shows a checkerboard but the background is still there. Why?
That is a screenshot: the checkerboard was drawn into the pixels. The file has no transparency, and no key can separate a painted pattern from a real one. Find the original file.
What does this tool output?
An 8-bit RGBA PNG at the exact pixel dimensions of the image you loaded, with the keyed colour removed and the edge rebuilt according to your tolerance and softness settings.
Does this site upload my PNG?
No. The removal runs in your browser and the image stays on your device.
Open the green screen remover — free, no account, and it writes a PNG with a real empty background at the size you loaded. If the file is already transparent, this page explains why running a remover over it again makes things worse.