Ditherlab
An image and ASCII dithering studio for macOS. Turn any photo, video, or webcam feed into 1-bit, halftoned, and ASCII art — nine error-diffusion kernels, ordered and blue-noise dithers, procedural halftones, four ASCII renderers, sixty-plus retro palettes, and GIF, MP4, and PNG export. Free, offline, on-device.
Download Ditherlab 1.2.1 for macOS — free (1.7 MB · macOS 13.5+, Apple Silicon & Intel)
First launch on macOS (one-time setup)
Ditherlab is free and open-source, so it isn't signed with a paid Apple certificate. On first launch macOS blocks it — on macOS 15 the message reads "can't be opened… this software needs to be updated". The app is fine; this is just Apple's warning for apps downloaded outside the App Store. To open it:
- Drag Ditherlab into your Applications folder (from the download window).
- Open it once — you'll see the block message. Click Done.
- Go to System Settings → Privacy & Security, scroll to Security, and click Open Anyway next to "Ditherlab". Enter your password.
- If no Open Anyway button appears, open Terminal and run:
xattr -dr com.apple.quarantine /Applications/Ditherlab.app
then open Ditherlab normally.
Needed once only. Ditherlab runs fully offline; the source is on GitHub.
