Last updated
Supported Formats
- Input: JPEG, PNG, WebP, GIF
- Output: JPEG or PNG (configurable quality)
- PNG with transparency: duotone applied to non-transparent pixels only
- All processing happens in your browser — images never leave your device
Use the Duotone Generator at techconverter.me to upload any image, choose your two colors, adjust intensity, and download the duotone result — or batch process multiple images at once.
Examples
Example 1: How the Duotone Effect Works
/* Process */
1. Convert image to grayscale
2. Map dark pixels → Color 1 (shadow color)
3. Map light pixels → Color 2 (highlight color)
4. Mid-tones blend between the two colors
/* Example mapping */
Grayscale 0 (black) → Shadow color (#1a1a2e, dark navy)
Grayscale 128 (gray) → Blend of both colors
Grayscale 255 (white) → Highlight color (#e63946, red)
Example 2: Spotify-Style Bold Color Combinations
/* Classic Spotify duotone palettes */
/* Pink + Yellow */
Shadow: #e91e8c (hot pink)
Highlight: #f9e900 (bright yellow)
Mood: Energetic, pop, youthful
/* Blue + Green */
Shadow: #1db954 (Spotify green)
Highlight: #191414 (Spotify black)
Mood: Brand-consistent, modern
/* Purple + Orange */
Shadow: #6200ea (deep purple)
Highlight: #ff6d00 (vivid orange)
Mood: Creative, bold, striking
/* Teal + Coral */
Shadow: #00695c (dark teal)
Highlight: #ff7043 (coral)
Mood: Warm, inviting, tropical
Example 3: Brand Color Duotone
/* Apply brand colors to team photos */
/* Brand: primary blue + white */
Shadow: #1e3a8a (brand dark blue)
Highlight: #ffffff (white)
Use case: Professional headshots, team page
/* Brand: dark + accent */
Shadow: #111827 (near black)
Highlight: #3b82f6 (brand blue)
Use case: Hero section backgrounds, feature images
/* Result: all team photos have consistent visual style */
/* matching the brand color palette */