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Image Tools

Image Duotone Generator

Create bold two-colour images in seconds. The duotone generator maps the darkest tones of a photo to one colour and the lightest to another, with smooth blends in between – the graphic style made popular by music streaming covers and modern brand campaigns. Choose from ready-made colour pairs or your own, adjust contrast and strength, and apply the look to a whole set of images.

  • Files stay on your device
  • No sign-up
  • Free to use

How to use Image Duotone Generator

  1. Drop one or more photos onto the page.
  2. Pick a colour pair or set the shadow and highlight colours.
  3. Adjust contrast and strength.
  4. Download the duotone images.

Image Duotone Generator features

Gradient map

Brightness mapped to two colours.

Colour pairs

Eight tested combinations.

Contrast

Punchier or softer tonal spread.

Strength

Blend with the original colours.

Batch

Apply the same settings to up to 50 images.

Private

Processed in your browser; nothing is uploaded.

When to use Image Duotone Generator

  • Social media graphics and campaign visuals.
  • Album, playlist and podcast covers.
  • Consistent hero images for a website.
  • Posters and event flyers.

Image Duotone Generator FAQ

What is a duotone?

Originally a printing technique using two inks to reproduce a photo. Digitally, it means mapping the image’s brightness onto a gradient between two colours.

Which photos work best?

Photos with clear subjects and good contrast, such as portraits and architecture. Busy, low-contrast images can look muddy; raise the contrast slider.

How do I choose colours?

Use a dark colour for shadows and a light, saturated colour for highlights. High contrast between the two – navy and pink, green and yellow – gives the strongest effect.

What does strength do?

At 100% the image is a pure duotone. Lower values let some original colour show through for a subtler tint.

Which formats can I use?

JPG, PNG, WebP, GIF (first frame), BMP and AVIF in; JPG, PNG or WebP out. PNG and WebP keep transparency; JPG gets a white background.

Are my images uploaded?

No. The images are processed in your browser and never leave your device.

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From printing press to brand style

Duotone printing was developed to give photographs more depth on printing presses: a second ink extended the tonal range of black-and-white images. Designers soon discovered the expressive power of unusual ink pairs, and the technique became a staple of posters and record covers.

The digital duotone is a gradient map. For every pixel, the tool calculates its luminance – how bright it appears to the eye – and looks up the colour at that position on a gradient from the shadow colour to the highlight colour. Black becomes the shadow colour, white the highlight colour, and every grey a blend of the two. Because the mapping is based on brightness, shapes and detail are fully preserved.

Contrast stretches or compresses the brightness before mapping. More contrast pushes tones towards the two pure colours for a graphic, poster-like look; less contrast keeps more blended tones. Strength mixes the duotone with the original colours.

Applying one colour pair to a whole series of photos is an easy way to give a website, a presentation or a campaign a strong, consistent identity, even when the photos come from different sources.

The images are processed locally in your browser.

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