macOS app · version 1.1.0

MacSlimFile

Image compression that runs entirely on your computer. No uploading to the cloud, no waiting on a server.

What it does

Compresses JPEG, PNG, WebP and AVIF — lossless or lossy. Images are processed in parallel, so even a large batch is done quickly.

It does more than compress. It converts formats, resizes images and renames a whole batch at once. Your favourite settings can be saved as a preset.

A faster alternative to Optimage. Free, no subscription.

Specs

Formats: JPEG, PNG, WebP, AVIF, plus HEIC as input
Compression: lossless and lossy
Conversion: to WebP, JPEG or PNG
Resizing: by long or short edge, width, height or percentage
Renaming: numbered sequence, custom name, prefix and suffix
Output: overwrite, copy alongside or a custom folder
Data: processed entirely on your Mac, nothing leaves it
System: macOS 15 or later, Mac with Apple Silicon
Language: English and Czech, following your system language

Download

Download MacSlimFile 1.1.0

Free · 4 MB · macOS 15 or later · Apple Silicon Macs only

First launch. The app isn’t notarized by Apple yet, so macOS will block it the first time. After your first attempt to open it, go to System Settings → Privacy & Security, scroll down and click Open Anyway. You only need to do this once.

MacSlimFile is free. If it saves you time, you can support me on Ko-fi

Questions and bug reports: napis@boruvka.cz