This page treats your picture as light on black. Brightness becomes opacity, so flames, sparks, smoke and lens flares stay soft and glowing on any background you put behind them.
Why a glow disappears in other tools
A tool that removes black by color decides, pixel by pixel, whether something is close to black. The faint outer part of a glow is close to black, so it is cut, and the effect you wanted ends at a hard edge. Light does not work like that: a glow is light added on top of darkness.
This page uses screen-to-alpha instead. Each pixel's opacity comes from its brightest channel, and its color is divided by that opacity. Put the result back over black and you get your original picture; put it over a photo, a gradient or a color and the light reads as light, faint edges included.
Settings
- Black point: pixels darker than this become fully transparent. Raise it a little to drop sensor noise or a dark haze that is not part of the effect.
- Brushes, lasso and wand still work on top, so you can erase a stray spark or a watermark.
- Flat black instead: for logos and line art on black, where you want a crisp edge rather than a glow. It switches to the color key with the same controls as the white-removal page.
Proving the glow survived
The export preview opens on gray rather than the checkerboard, because a glow is easy to misjudge on a pattern. Try it on a color too, from the background tab, before you save. If the effect looks washed out, the black point is probably too high.
Save as PNG or WebP to keep transparency. JPEG cannot hold it and would fill the background with white, which is rarely what you want for a light effect.
What it is not for
Screen-to-alpha makes every dark part of the picture transparent, including dark parts of a solid subject. A person or a product photographed on black is a job for detection: use the main remove background page, which keeps a solid subject solid. This page is for light: fire, sparks, smoke, stars, bokeh, neon, light leaks and particle effects.
Step by step
- Open the effect. Drop a picture of light on a black background.
- Check on gray. The preview shows the glow on mid-gray.
- Set the black point. Raise it slightly to remove noise or haze.
- Clean up. Erase stray marks with the brush or lasso.
- Save PNG or WebP. Both formats keep the transparency.
Questions people ask
Key or screen-to-alpha: which should I use?
Screen-to-alpha for anything that glows or fades: fire, smoke, sparks, light. The flat black key for logos, text and line art where you want a crisp edge.
Which format keeps the glow?
PNG and WebP both store the partial transparency a glow needs. JPEG has no transparency at all.
Why does my subject look see-through?
Screen-to-alpha makes dark areas transparent, including dark parts of a solid object. For a solid subject on black, use the remove background page, which detects the subject instead.
Does it need a model download?
No. The calculation runs on your device immediately, without a model.
Will the result look the same on black as my original?
Yes. Placed over pure black it reproduces the original picture, which is the point of the method.