Rainbow filter
Map brightness to a full-spectrum rainbow. Nothing is uploaded.
- Your files are never uploaded
- Processed on your device
- Works offline
- Free, no sign-up
Drop your images here
Images · up to 10 files, 100 MB each
or paste with Ctrl+VLive preview
Settings
PNG keeps every shade exactly. JPG and WebP use the quality below.
Used for JPG and WebP only. PNG is always saved losslessly.
How it works
Add your images
Choose up to 10 images — JPG, PNG, WebP, GIF, BMP, AVIF or HEIC — straight from your device.
Tune the effect
Nothing to adjust — brightness is mapped to rainbow colors automatically.
Download the result
Preview each filtered copy, then save them one by one or all together as a ZIP.
Paint with pure spectrum
This filter reads each pixel's brightness and repaints it as rainbow color: shadows glow red, mid-tones pass through green and yellow, and highlights shine violet. Ordinary scenes become psychedelic maps of light.
Portraits turn into pop art, architecture becomes stained glass, and dull graphs become unforgettable. Every result is unique to the light in your original shot.
Choosing the right source
High-contrast black-and-white images give the cleanest rainbows, because the full gradient gets used. Flat grey pictures collapse into a narrow band of greenish tones.
Try it on the output of the dithering or threshold tools for striking poster art. PNG keeps the spectrum crisp; JPG keeps the file small for social posts.
Your light show, privately
The spectrum mapping happens in a worker thread on your own processor. Your images are decoded, recolored and re-encoded without a single byte leaving the building.
No gallery, no cloud, no audience. Make as many rainbow versions as you like, download them, and the show stays yours alone.
Questions
Are my images uploaded when I use this?
No. Everything runs inside your browser on your own device. Your files are never sent to us or to anyone else.
How does the rainbow mapping work?
Each pixel's brightness picks a color from a red-to-violet gradient: dark pixels turn red, bright pixels turn violet, with the full spectrum in between.
Does it keep any original color?
No. Every pixel is recolored purely from its brightness, so the original hues are fully replaced by the spectrum.
Is it free?
Yes. Free to use, with no sign-up, no watermark and no daily limits.
Related tools
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