Export Multi-Resolution Favicon ICO in GIMP

This guide explains how to create and export an optimized, multi-resolution .ico favicon file using GIMP. Because modern web browsers and operating systems display favicons across varied display densities and UI elements, combining multiple dimensions (such as 16x16, 32x32, and 48x48 pixels) into a single .ico container ensures sharp rendering everywhere. In GIMP, this multi-resolution packaging is accomplished by treating each individual layer as a separate icon size during export.

1. Create the Base Canvas

  1. Open GIMP and click File > New.
  2. Set the Width and Height to 256 x 256 pixels.
  3. Expand Advanced Options and set Fill with to Transparency.
  4. Click OK.
  5. Design your icon on this layer. Ensure your design remains legible even when shrunk to small sizes.

2. Create Layers for Standard Favicon Resolutions

Standard .ico files typically require three core dimensions: 16x16 (browser tabs), 32x32 (taskbars/desktop shortcuts), and 48x48 (high-DPI screens or file managers).

  1. Duplicate your base design layer three times in the Layers panel.
  2. Rename each layer corresponding to the target dimension: 256x256, 48x48, 32x32, and 16x16.
  3. Scale each layer individually:
    • Select the 48x48 layer, go to Layer > Scale Layer..., set dimensions to 48 x 48, ensure Interpolation is set to Cubic or NoHalo, and click Scale.
    • Repeat the scaling step for the 32x32 layer (set to 32 x 32).
    • Repeat the scaling step for the 16x16 layer (set to 16 x 16).

3. Clean Up Low-Resolution Layers (Optional)

Downscaled images at 16x16 often lose sharpness. Select the 16x16 and 32x32 layers individually and apply a slight unsharp mask (Filters > Enhance > Sharpen (Unsharp Mask)) or manually touch up blurry edges using the Pencil tool with an opacity of 100%.

4. Export as a Multi-Layer .ico File

  1. Go to File > Export As....
  2. Set the file name to favicon.ico.
  3. Ensure the file extension is .ico or choose **Microsoft Windows Icon (*.ico)** from the file type list at the bottom.
  4. Click Export.

5. Configure the Export Options Dialog

GIMP will open the Export Image as Windows ICO dialog listing all active layers.

  1. Bit Depth Settings:
    • For the 16x16, 32x32, and 48x48 layers, select 32 bpp, 8-bit alpha, no palette. This retains full-color depth and anti-aliased transparency.
    • For the 256x256 layer (if retained), you can select Compressed (PNG) to significantly reduce the overall file size.
  2. Ensure every layer you want to include has the Compressed (PNG) or standard 32 bpp profile selected based on your size preferences.
  3. Click Export to finalize the .ico file.