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Duotone Image Image

Map an image onto two colors for a bold editorial look.

Duotone Image is a free online tool that map an image onto two colors for a bold editorial look. It accepts JPG, PNG, WEBP, GIF, BMP, AVIF and SVG — anything your browser can display. It produces pNG by default.. It runs entirely in your web browser using Canvas 2D, so files are processed on your own device and never uploaded to a server. There is no sign-up, no file size limit imposed by the site, no watermark and no paid tier.

Price
Free — no account, no quota, no watermark
Category
Image
Where it runs
In your browser, on your device
Files uploaded
None
Input
JPG, PNG, WEBP, GIF, BMP, AVIF and SVG
Output
PNG by default
Technology
Canvas 2D
Settings
2
Works offline
Yes, after the first visit

About Duotone Image

Every pixel is reduced to a single brightness value, then mapped onto a straight line between your two chosen colors. Shadows land on the first color, highlights on the second, everything else in between. Picking two colors far apart in hue gives the strong editorial look; picking near neighbors gives a subtle tint.

How to use it

  1. Choose an image, or drag one onto the drop zone.
  2. Set shadow color and highlight color.
  3. Check the preview, then download. Your original file is never modified.

The 2 settings

SettingWhat it doesDefault
Shadow colorA color, picked from your system color picker.#0b1120
Highlight colorA color, picked from your system color picker.#ffd84d

Under the hood

Runs onCanvas 2D — does the pixel work
AcceptsJPG, PNG, WEBP, GIF, BMP, AVIF and SVG — anything your browser can display
ProducesPNG by default
ControlsShadow color, Highlight color

Questions

Why does my duotone look flat and muddy?

The two colors are probably too close in lightness. Duotone relies on the brightness gap between them — pair a dark shadow color with a genuinely light highlight color.

Which file types can I use?

JPG, PNG, WEBP, GIF, BMP, AVIF and SVG — anything your browser can display. Because decoding is handled by your browser rather than a conversion server, support tracks whatever your browser can already open.

Is there a file size limit?

No imposed limit — there is no server quota to hit. The real ceiling is your device's memory, since the whole file is held in RAM while it is processed. Desktop browsers cope with very large files; phones give up sooner.