Duotone Photo Effect & Gradient Map Online
Recolour a photo through a two- or three-stop colour ramp, the Spotify-style duotone look, with full gradient-map control.
Duotone maps an image's brightness onto a colour ramp instead of its original hues: dark areas take the shadow colour, bright areas the highlight colour, and everything between is interpolated. Add a midtone stop and it becomes a full gradient map. Blend it back against the original when you want a tint rather than a full replacement.
How to Use It
- Upload your image and wait for the local preview to load.
- Adjust the settings: Pick a colour ramp or set custom shadow, midtone and highlight stops, then tune effect strength and tonal contrast.
- Download the result: Download the processed file directly to your device.
Controls and Options
Lower effect strength for a tint instead of a full recolour; raise tonal contrast when a flat photo uses only part of the ramp.
Formats and Output
Input: JPG, PNG, WebP. Output: JPG, PNG, or WebP. PNG keeps flat colour bands cleanest for print and poster use.
Frequently Asked Questions
What is the difference between duotone and a gradient map?
A duotone uses two colours. One for shadows, one for highlights. A gradient map is the general case: any number of stops along the brightness range. Turning on the midtone stop here moves you from the first to the second.
Why does it follow brightness rather than colour?
The ramp is indexed by Rec. 709 luma, so the recolour tracks perceived brightness. That is what keeps faces and textures readable instead of collapsing into flat patches.
Can I keep some of the original colour?
Yes. Lower the effect strength and the ramp is mixed back over the original pixels, which gives a tint rather than a full replacement.
Which images work best?
Images with a clear tonal range. Very flat or already low-contrast photos produce a narrow band of the ramp. Raising tonal contrast first usually helps.
Is my photo uploaded anywhere?
Supported image content is not uploaded for processing. The ramp is built and applied in your browser; site analytics and the assistant are separate.