PNG8 Converter: 256-Colour PNG with Transparency

PNG8 is a PNG that uses an indexed palette of at most 256 colours instead of storing full colour for every pixel. Each pixel then needs only a single byte, so files are typically much smaller than full-colour PNG24 or PNG32, often by 60 to 80% for flat graphics. Modern PNG8 also supports full alpha transparency through the palette, so soft edges survive.

The PNG8 Converter reduces each image to an optimized palette of up to 256 colours with a quantization algorithm and writes a PNG; if the full-colour version happens to be smaller, which can occur with very simple images, that one is kept instead. Lower the quality slider to use fewer colours (128, 64, 32 or 16) for even smaller files.

How to use the PNG8 Converter (256 Colours)

1. Drop your images onto the upload area, click it to choose files, or paste an image with Ctrl+V. This page accepts PNG, JPG, GIF and BMP files, many at once and up to 80 MB each.
2. The default quality of 90 gives the full 256-colour palette. Lower it to 70 to 84 for 128 colours or 50 to 69 for 64 colours when the graphic is simple; the line under the slider shows the colour count.
3. Check gradients and soft shadows in the before/after view. If you see banding, go back to 256 colours or use lossless output.
4. Check the result with the before/after slider: drag the divider across the preview and read the new dimensions, file size, quality and percentage saved underneath. Any change to the settings re-processes every image automatically.
5. Download a single image, or use Download all (ZIP) for the whole batch. Under More options you can also set a DPI value and a file-name pattern with {name}, {w} and {h}.

When PNG8 is the right format

• Icons, logos and buttons with flat colours usually look identical at 256 colours or fewer.
• Charts, diagrams and UI screenshots with limited colours shrink a lot while staying sharp.
• Legacy systems that expect indexed-colour PNG, such as some embedded displays and older software.
• Not for photos. Photographs need far more colours; use JPG or WebP instead, or the TinyPNG-style optimizer for adaptive palettes.

Like any colour reduction, PNG8 is lossy. Keep your full-colour originals so you can return to them if you need more colours later. A practical approach is to try 256 colours first, then step down to 128 or 64 while watching the before/after slider, and stop at the smallest palette where edges, shadows and brand colours still look right.

Private, free and fast

The whole job runs in your browser: images are decoded, resized and re-encoded on your own device, so nothing is uploaded to a server. There is no sign-up, no watermark and no daily limit, and location and camera data (EXIF) are removed from every result.