Remove a green screen
A photo taken against a green or blue screen, back as a transparent PNG at full resolution. The screen, its shadow and the green cast on hair all go.
- No uploads
- No sign-up
- No file limit
- No watermark
nothing was uploaded
Why the shadow usually stays, and why it does not here
The obvious way to key a screen is to measure how far each pixel's colour is from the screen's colour and remove everything close to it. It works on the lit part of the wall and fails everywhere else, because a shadow on a green wall is a long way from bright green. That is the grey lump in the corner of every disappointing key.
Here the distance is measured in colour divided by brightness. Dark green and bright green have the same hue and the same saturation relative to how much light there is, so a shadow across the backing counts as the same colour as the backing and goes with it. Your eye has been saying that all along.
Spill, and why a saturation slider is the wrong fix
A subject standing in front of a green wall is green: along the shoulders, under the chin, and right through any loose hair. The usual fix, pulling the saturation down in that area, removes the colour and leaves a grey smear that looks worse than the spill did.
Spill is a push in one direction in the colour plane. Subtract that push and the pixel lands where it would have been without the wall. Doing it at exactly the brightness the camera recorded is what keeps hair looking like hair: it loses its cast and keeps its shape.
The thresholds come from your picture
A backing is never one colour. It is lit unevenly, it creases, and a phone sensor adds noise on top. Fixed thresholds therefore suit one picture and no other. When your file arrives, the spread of colours along the border of the frame is measured and the tolerance is set past nearly all of it, so an evenly lit studio screen gets a tight key and a bedsheet under one lamp gets a looser one. Both sliders are still yours to move.
When you have no screen
Use the background remover on the front page instead: it runs a segmentation model and needs no screen at all. The rule of thumb is that a key follows the true edge of the subject wherever the backing shows through, including every gap between strands of hair, which no model can match; and a model works on a photo taken in a kitchen, which no key can. If you shot against a screen, key it.
What comes out
A PNG with a real alpha channel at the size you brought, which is what a slide, a document, a thumbnail or a video editor wants. Or the same cutout on a solid colour of your choice, which is what a marketplace listing wants. Nothing is watermarked and nothing is resized.
Guides that go further
Part of green screens and chroma keying. What each format is, when to use it, and what to do when a file will not open.
- Green screen, from the wall to the finished cutoutWhy green, how to light a screen so the key is easy, what a keyer actually does, and when a green screen beats an AI background remover and when it does not.
- Chroma key explained: how software decides what is backgroundWhat a chroma key measures, why naive keyers leave shadows behind, what tolerance and softness really control, and how spill suppression should work.
- Green screen or AI background removal: which to useAn honest comparison of chroma keying and AI cutouts: where each wins on hair, glass and speed, and how to combine them when one is not enough.
- Green screen spill: why the edges go green and how to fix itWhat causes the green rim around a keyed subject, how to prevent it in the room, and why a saturation slider is the wrong way to remove it.
Questions
How do I remove a green screen from a photo?
Drop the photo on this page. The screen colour is found from the edge of the frame and keyed out straight away, so the first thing you see is usually the answer. If the shot needs a nudge, the tolerance, the softness of the edge and the amount of spill removal are all sliders, and clicking the backing sets the key colour by hand. Download a transparent PNG at the size you brought.
Does it work with a blue screen, or any other colour?
Yes. Nothing here is specific to green: the key is whatever colour the backing is, and blue, grey, red or a bedsheet all work the same way. Blue screens are common for anything with green in it, which is the whole reason they exist.
Why do other tools leave a grey lump where the shadow was?
Because they measure how far each pixel's colour is from the key colour, and a shadow on a green wall is a long way from bright green. Here the distance is measured in colour divided by brightness, so a shadow on the backing counts as the same colour as the lit part of it and goes with it. That one change is the difference between a clean key and an afternoon of masking.
What is spill, and what does the spill slider do?
Spill is the green a wall throws back onto whatever is in front of it: along shoulders, under the chin and right through loose hair. Turning the saturation down kills it and leaves a grey smear. The slider here subtracts the key colour's own hue from the pixel while keeping exactly the brightness the camera recorded, so hair keeps its shape and loses its cast.
Should I use this or the AI background remover?
If there is a screen in the shot, use this: a key follows the actual edge of the subject, including every gap between strands of hair, which no model can match. If there is no screen, use the background remover on the front page, which needs no screen at all. Both run in the browser and neither uploads anything.
My screen is lit unevenly. Will it still work?
Usually. The thresholds are not fixed: the spread of colours along the border of your picture is measured when the file arrives, so an evenly lit studio screen gets a tight key and a creased sheet under one lamp gets a looser one. If a patch is still left behind, raise the tolerance a little; if the edge of the subject is being eaten, lower it and raise the softness instead.
Can I put a new background behind it?
Yes, a solid colour of your choice, or transparency, which is what you want if the next step is a document, a slide or a video editor. A JPG cannot hold transparency, so choosing JPG with a transparent background gives you white and the page says so before you save.
Does it work on video?
Not here: this is a photo tool. It is very good on a frame exported from a video, on a product shot taken against a screen, and on a still for a thumbnail. For moving footage, the keyer built into your editor is the right tool, and the guides linked below cover setting up the screen so that key is easy.
Is my photo uploaded?
No. The keying is arithmetic per pixel, done in this browser tab, and there is no address on this site that could receive a picture. Once the page has loaded it works with no connection at all.
Your files never leave this device
Most online converters upload every file to a server, convert it there and keep it for a while. Here your browser decodes and encodes the picture itself, so there is nowhere for the file to go. You can check it: load this page, switch the browser to offline, and convert a file. How to check a site is not uploading your photos.