An ImageOptim alternative for Mac, when free stops being enough

ImageOptim is good. Here is where people outgrow it.

ImageOptim has been a staple of Mac web workflows for over a decade, and for lossless PNG and JPEG crunching it is still excellent. It is free, open source, runs entirely on your machine, and strips metadata by default. If that is all you need, it remains a perfectly good answer.

The reasons people go looking for an alternative are usually specific rather than general. Modern web work has moved to AVIF and WebP. Photographers arrive with RAW files. Designers need the 40 MB InDesign PDF to become an email attachment. Nobody wants a second app for video. And there is a ceiling on how small a purely lossless pass can make a photograph, no matter which encoder runs it.

• Modern formats — Smol writes AVIF and WebP, typically 30–50% smaller than JPEG at equivalent quality.
• RAW support — drop CR2, NEF, ARW or DNG straight from the camera.
• PDFs — five quality presets, from 72 DPI email-ready to print-quality 300 DPI.
• Video — H.265/HEVC for MP4, MOV, AVI, MKV and WebM, roughly 40–60% smaller.
• AI upscaling — enlarge 2× or 4× locally, no API key or cloud round-trip.

What Neural compression actually does differently

Conventional compressors apply the same quality setting across the whole frame. A face and an out-of-focus wall get treated identically, which means you either spend bits on the wall or lose detail in the face.

Smol builds an importance map before it encodes. It marks faces, text, object edges and fine texture as regions to protect, and smooth backgrounds, sky and shadow as regions it can compress much harder. The bits go where people actually look. In practice that means JPEG images landing 60–85% smaller, and PNG files 30–60% smaller losslessly, while the details that carry the picture stay crisp.

If compressing a file would somehow make it larger, Smol keeps the original. You never end up with a worse file than you started with.

Still 100% local — nothing is uploaded

This is usually the reason someone chose ImageOptim in the first place, so it is worth being direct: Smol does not upload your files. There is no account, no server, no upload queue and no processing quota. Every encoder ships inside the app and runs on your own CPU and GPU.

That also makes it fast. Online compressors spend most of their time moving your file across the network twice. A 100 MB video that takes minutes through a browser tool finishes in under 30 seconds locally. And you can strip EXIF, GPS, IPTC and XMP metadata without recompressing, so the pixels stay untouched while the identifying data goes away.

Batch work and the parts of the day you repeat

Drag a folder of 500 mixed files — images, PDFs and videos together — and Smol processes the lot, showing per-file progress and per-file savings. Virtual scrolling keeps the window responsive past 1,000 items, and you can cancel mid-run or re-optimise individual files afterwards.

For the small repeated jobs there is a menu bar tray, a Finder Quick Action, and clipboard compression: copy a large image, paste a small one. These are the interactions that add up over a working week.

Smol vs ImageOptim

Frequently asked questions

Is Smol a drop-in replacement for ImageOptim?

For image compression, yes — drag and drop works the same way, everything runs locally, and metadata stripping is built in. Smol goes further with AVIF and WebP output, RAW files, PDFs, video and AI upscaling. The main difference is that ImageOptim is free and open source while Smol is a one-time $29 purchase.

Why pay for an alternative when ImageOptim is free?

You should not, if lossless PNG and JPEG is all you need — ImageOptim is very good at that and costs nothing. Smol earns its $29 when you need modern formats like AVIF, RAW support, PDF and video compression in the same app, or Neural compression that protects faces, text and edges while compressing backgrounds harder.

Does Smol upload my images anywhere?

No. Every file is processed entirely on your Mac using encoders bundled inside the app. There are no accounts, no servers and no upload queue. Your images never leave your device — the same privacy guarantee that draws people to ImageOptim.

Can Smol strip EXIF and GPS data like ImageOptim does?

Yes. Enable "Strip metadata" and Smol removes EXIF, GPS, IPTC and XMP data — camera model, coordinates, timestamps and author fields. You can strip metadata without recompressing, so the image content stays pixel-for-pixel identical while the identifying information is removed.

Does Smol work on Intel Macs?

Yes. There are separate native builds for Apple Silicon and 64-bit Intel with identical features. Apple Silicon requires macOS 13 or later; Intel requires macOS 14 or later.

Is it a subscription?

No. Smol is $29 once, including future updates. No renewal, no recurring fee, no per-file quota.