Frostbatch is a macOS app for resizing, converting and compressing images in batches. Set a width, pick a format, or tap a preset for wherever the images are going. It writes the whole set in one pass, on your machine.
Four settings decide the output: where it goes, what shape it is, what format it is written in, and whether to upscale first. Everything else stays out of the way until you need it.
Real‑ESRGAN rebuilds detail at 4× before the resize, on your Mac's GPU. Two models: Photo for camera work, Illustration for flat art and line work. Slow, and worth it when the source is small.
Web development, e‑commerce, blogging and social, photography, office. A preset loads its numbers straight into the sidebar, so you can see what it will do and change it. A bundle writes several sizes from one source in a single run.
Point Frostbatch at a folder and anything dropped into it is processed on arrival, with your current settings or a separate set saved for that folder.
Strip EXIF, GPS and camera data before you share. Nothing is uploaded; there is no account and no server.
Give the batch a filename pattern. {name} keeps the original, so {name}@2x turns hero.jpg into hero@2x.jpg.
Drag a frame on any single image. The crop is applied before the resize and stays saved if you reopen it.
Captured from the shipping build, not mocked up.
HEIC from an iPhone opens like anything else, and writes out as JPEG when you ask for the original format, since there is no HEIC encoder to write back to.
Five days of the full app, then $9.99 through the App Store. No subscription, no credits, no account.
The whole app for five days. No card, no account, nothing to cancel.
One purchase, no subscription. Every preset, watch folders and AI upscaling included.
No. It is $9.99 once, through the Mac App Store, and the app is yours. There is no account to make and nothing to renew.
You get five days of the full app. After that, starting a new batch asks you to unlock it for $9.99. Nothing you have already exported is touched, and there are no prompts before the five days are up.
No. Every resize, conversion and upscale runs on your Mac. The AI model ships inside the app, so upscaling works with the Wi-Fi off. Frostbatch has no analytics, no telemetry and no server of its own.
It runs Real-ESRGAN over each image at 4× before the resize, which rebuilds detail rather than stretching pixels. Two models are bundled: Photo for camera work, Illustration for flat art and line work. It is much slower than a plain resize, and it earns that time on small sources, not on a 4000px original.
It needs macOS 13 (Ventura) or newer. It is a Universal Binary, native on Apple silicon and Intel. Upscaling uses the GPU where there is one and falls back to the CPU otherwise.
Not at the moment. The Mac App Store is the only place to buy it.
It reads JPG, PNG, WebP, AVIF, TIFF and HEIC, and writes the first five. Pick Original to keep each file's own type; HEIC is the exception and comes out as JPEG, because there is no HEIC encoder to write back to.
Either into a zip you choose the location for, or over the originals in place if you pick Rewrite. The zip is named batch- plus a timestamp by default, and you can change that prefix.
Five days free, then $9.99 once. macOS 13 or newer.