How to Export 8-Bit and 16-Bit PNG in GIMP

This guide explains how to configure GIMP to export PNG files in either 8-bit or 16-bit integer formats. By adjusting the image precision and using the PNG export dialog's pixel format settings, you can ensure your final file maintains the right balance between color fidelity and file size.

Step 1: Set the Image Precision

Before exporting, ensure your working canvas matches the bit depth you intend to output.

  1. Open your image in GIMP.
  2. In the top menu, go to Image > Precision.
  3. Choose either 8-bit integer or 16-bit integer.
  4. If converting down from a higher bit depth, select your preferred dithering options in the prompt that appears to prevent banding.

Step 2: Open the PNG Export Dialog

  1. Navigate to File > Export As...
  2. Name your file with the .png extension (e.g., output.png) or expand Select File Type (By Extension) at the bottom and choose PNG image.
  3. Click Export to bring up the Export Image as PNG options dialog.

Step 3: Select the Pixel Format

In GIMP 2.10 and newer, the PNG export dialog provides direct control over the channel bit depth:

  1. Locate the Pixel format dropdown menu in the export options window.
  2. Open the dropdown to select your desired bit depth:
    • For 8-bit: Select 8bpc RGB (or 8bpc RGBA if your image contains transparency) or 8bpc GRAY for grayscale.
    • For 16-bit: Select 16bpc RGB (or 16bpc RGBA with transparency) or 16bpc GRAY.
    • Selecting Automatic will automatically match the depth currently assigned under Image > Precision.
  3. Adjust compression levels or metadata toggles as needed.
  4. Click Export to save the file.