Macview

Macview opens a picture in a window the size of the picture, on a plain dark ground, and then gets out of the way. There is no toolbar, no sidebar and no title bar, and the image runs to the edges of the window. The arrow keys step through the rest of the folder, files and folders can be dropped on the window, and that is the whole interface.

It reads whatever macOS itself reads - JPEG, PNG, GIF, TIFF, HEIC, WebP, AVIF, JPEG XL and the camera RAW formats - because the decoding is done by the system's ImageIO rather than by a bundled library. Animated GIF, APNG, animated WebP and HEICS play on the frame delays written in the file, and their frames are decoded one at a time as they are needed rather than unpacked into memory up front.

Nothing is bundled. The app links only macOS frameworks, so the whole thing is under 2 MB with its icon and under 200 KB of code, and a window is on screen about half a second after launch. It is deliberately a viewer and nothing else: no saving, no exporting, no editing, no renaming and no deleting.

Requires macOS 14 Sonoma or later on Apple silicon. Free and open source under the MIT licence.