I make Picmal, one of the 7 apps here. So I didn’t rank them. I put each one where it fits, by what you need, and I tested Picmal on public files you can download yourself.
I didn’t test the other 6. What I write about them comes from their makers’ own websites, checked on 15 October 2026, and each section says so.
First, ImageOptim itself
ImageOptim is free and open source, and it’s still maintained. Version 1.9.3 is current, and the project had a commit on GitHub in July 2026. It runs on macOS 11 or later.
It shrinks JPEG, PNG, GIF and SVG files with MozJPEG, pngquant, Zopfli and SVGO, and strips EXIF and GPS data on the way. Lossy compression is optional, switched on in Preferences. It also works from Finder’s Services menu and the command line.
If those 4 formats are all you handle, keep it. People look elsewhere for one reason: ImageOptim compresses, it doesn’t convert. A HEIC from your iPhone stays a HEIC, and a PNG can’t become a WebP or an AVIF.
The short answer
- Free, in the browser: Squoosh keeps your images on your device. TinyPNG uploads them.
- Compression that runs on its own: Zipic, free for 25 images a day or $29.99 once.
- Images, video and PDF made smaller: Optimage ($15) or Compresto (from $49). For a PDF on its own, see how to compress a PDF on Mac.
- Watermarks and filters in the same batch: Squash, $29.99.
- Compress and convert to WebP, AVIF or JPG: Picmal, $29 once.
Quick comparison
| App | Price | Handles | Where it runs | Tested here |
|---|---|---|---|---|
| ImageOptim | Free | JPEG, PNG, GIF, SVG | Your Mac | No |
| Squoosh | Free | Images | Your browser | No |
| TinyPNG | Free (20 per session) or from about $39 a year | Images | Their servers | No |
| Zipic | Free (25 a day) or $29.99 once | Images, PDF | Your Mac | No |
| Optimage | Free (24 a day) or $15 | Images, video, PDF | Your Mac | No |
| Compresto | $49 once | Video, images, GIF, PDF | Your Mac | No |
| Squash | $29.99 | Images | Your Mac | No |
| Picmal | $29 once | Images, video, audio, PDF | Your Mac | Yes |
How I tested Picmal
I ran it on my own Mac, an Apple M3 with 16 GB and macOS 27.0.1, using picmal-cli 2.0.0. The command line uses the same bundled tools as the app, and it gives clean timings. Every test used Picmal’s default settings.
The files are public, so you can repeat it. I used the Kodak Lossless True Color Image Suite, 24 photos as PNG, 14.7 MB. I made JPG (quality 92) and HEIC copies with macOS’s own sips.
Each time is the middle of 3 runs.
| Job | Time | Result |
|---|---|---|
| 24 JPG compressed | 0.46 s | 4.0 MB to 1.8 MB (55% smaller) |
| 24 PNG to WebP | 1.05 s | 14.7 MB to 1.1 MB |
| 24 PNG to AVIF | 1.85 s | 14.7 MB to 0.8 MB |
| 24 PNG to JPG | 0.56 s | 14.7 MB to 3.5 MB |
| 24 HEIC to JPG | 0.86 s | 24 JPGs, 3.1 MB |
The JPG line is the one to put next to ImageOptim. The other 4 are jobs ImageOptim doesn’t do.
If you want it free, in the browser
Squoosh
Squoosh is a free, open source web app that compresses images. Your images never leave your device, even though it runs in a browser tab. Its last commit on GitHub is from August 2024.
Pick it if you want to try a setting on one image before you commit to an app.
Not tested by me. Facts from squoosh.app.
TinyPNG
TinyPNG compresses and converts AVIF, JPEG XL, WebP, JPEG, PNG and APNG, and sends HEIC uploads back as JPG. The website is free for 20 images per session, 5 MB each. Web Pro is about $39 a year, and the API gives 500 free images a month.
It’s a web service. Your files go to its servers and stay there for up to 48 hours. Every other app in this list keeps them on your machine.
Pick it if the images are already public and you don’t want to install anything.
Not tested by me. Facts from tinypng.com.
If you want compression to run on its own
Zipic
Zipic compresses, converts and resizes 12 image formats, PDF and SVG among them, with 6 compression levels. It watches folders, compresses whatever you copy to the clipboard, and takes files dropped on the MacBook notch. It also works from Finder, Shortcuts, Raycast and a command line tool.
After a 7-day Pro trial it’s free for 25 images a day in basic formats. Personal is $29.99 once for 2 devices. It needs macOS 13 or later.
Pick it if you want screenshots and exports to come out small without you dragging them anywhere.
Not tested by me. Facts from zipic.app.
If you also shrink video and PDF
Optimage
Optimage compresses and converts images, video (MP4, WebM, HEVC, ProRes, AV1) and PDF. The maker calls its compression “visually lossless”. It also resizes, converts and renames in batch, removes metadata, and has a command line tool and Finder integration.
It’s free for 24 images a day, or $15. It runs on macOS 10.13 or later, the oldest Macs in this list. The latest entry in its version history is from 26 November 2021.
Pick it if you’re on an older Mac and also need video and PDF smaller.
Not tested by me. Facts from optimage.app.
Compresto
Compresto compresses video, images, GIF, PDF and EPUB, and turns video into GIF. It watches folders, has a Drop Zone and works from Raycast. The maker says files come out up to 90% smaller; I didn’t check that.
It’s $49 once for one Mac, $69 for two, or a subscription, and it’s on Setapp. It needs macOS 13 or later. The demo on its pricing page uses Compresto’s server; the app runs offline.
Pick it if your problem is a folder of screen recordings, not a format.
Not tested by me. Facts from compresto.app.
If you edit while you batch
Squash
Squash, from Realmac Software, converts, compresses and resizes images, and adds layered watermarks, 8 filters and metadata edits in the same batch. Presets save a batch you run often, and it works with Shortcuts.
It’s $29.99, with Effect Packs sold separately. It needs macOS Big Sur or later.
Pick it if every batch of product photos also needs your logo on it.
Not tested by me. Facts from realmacsoftware.com.
If you also need other formats
Picmal
Picmal is the one I make, and the one I tested above. It compresses and converts images (HEIC, RAW, SVG, PSD and the usual ones) in batches, without leaving your Mac. It also handles video, audio and PDF, watermarks images and videos, crops images and PDFs, and lets you strip all metadata, keep only the essential, or keep all of it.
It lives where you already work: Finder’s right-click menu, Shortcuts, Raycast, watched folders and a command line tool. It needs macOS 15 or later.
It’s $29 once for one Mac, with a 7-day free trial and a 14-day refund. No subscription.
What it doesn’t do: run on a Mac older than macOS 15, run in a browser, or cost nothing. If you need any of those, ImageOptim, Squoosh or Optimage are the better pick.
Frequently asked questions
Is ImageOptim still worth using in 2026? Yes, if your files are JPEG, PNG, GIF or SVG and you only want them smaller. It’s free, open source and still maintained: version 1.9.3, with a commit on GitHub in July 2026. It doesn’t convert formats, so for WebP, AVIF or HEIC you need a second app.
Which ImageOptim alternative is free? Squoosh is a free web app, and your images stay on your device. TinyPNG’s website is free for 20 images per session, but it uploads them. Optimage is free for 24 images a day, and Zipic for 25 a day in its basic formats after a 7-day trial.
Do any of these alternatives upload my files to the internet? TinyPNG does. It’s a web service, and it keeps your files on its servers for up to 48 hours. Picmal, Zipic, Optimage, Squash and Compresto run on your Mac, and Squoosh keeps images on your device, according to their makers.
Can I convert HEIC to JPG with these tools? ImageOptim can’t: it reads JPEG, PNG, GIF and SVG. Picmal converted 24 HEIC photos to JPG in 0.86 seconds in my test. TinyPNG sends HEIC uploads back as JPG. For the others, check the format list on the maker’s site.
How much does Picmal compress a JPG? On an M3 Mac, Picmal 2.0 compressed 24 JPG photos from 4.0 MB to 1.8 MB, 55% smaller, in 0.46 seconds, with default settings. The test files are public, and the method is in the article.
Weighing Picmal against one app in particular? There’s a side-by-side page for ImageOptim, Zipic and Compresto.
If compression is the whole job, here’s how to compress images on Mac with Picmal. For a camera roll of iPhone photos, see how to convert HEIC to JPG on Mac. For images headed to a site, see how to compress images for a website. And if you convert more than you compress, there’s a comparison of batch image converters.
