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Classic Mac OS 16-Colour Filter

When the Macintosh II brought colour to the Mac in 1987, classic Mac OS defined a standard 16-colour palette for 4-bit displays: the colours of early colour icons, HyperCard stacks and shareware games. This tool maps your image onto that palette with dithering, keeping the full resolution.

  • Processed locally
  • No upload, no wait
  • No sign-up
  • No watermark

Drop images here

or choose files · paste with Ctrl/⌘ V

JPG, PNG, WebP, HEIC, AVIF, GIF, TIFF, SVG, RAW, PSD, JXL, BMP, ICO and more

Files are processed on this device. Nothing is uploaded.0 B uploaded

How to use Mac 16 Colours

  1. 1

    Drop your images, choose files, or paste from the clipboard.

  2. 2

    Adjust the options. The preview updates as you change them.

  3. 3

    Click Apply. Files are processed on your device.

  4. 4

    Download each result or everything as a ZIP.

Why use Aback Images for mac 16 colours

Real hardware palettes

Colours from the NES, Game Boy, PICO-8, Commodore 64, IBM CGA and EGA, classic Mac OS and 1 and 2-bit greys, rather than a palette guessed from your image.

Chunky pixels on demand

Set how many pixels across the picture should be, from full resolution down to a few dozen.

Dithering

Optional dithering mixes palette colours to suggest shades a small palette lacks.

Processed on your device

Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.

About Mac 16 Colours

Limitations

  • Each pixel is mapped to the nearest colour in the palette. Real hardware also limited how many colours could share a tile or a scanline; those rules are not applied, so photos keep more colour variety than the original machine could show.

Frequently asked questions

Which colours are in the Mac 16 palette?

White, yellow, orange, red, magenta, purple, blue, cyan, green, dark green, brown, tan, light grey, medium grey, dark grey and black: the standard 4-bit palette of classic Mac OS.

Are my images uploaded anywhere?

No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.

Can I process many files at once?

Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.

Is it free? Is there a file limit or watermark?

It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.