The best ImageOptim alternatives for Mac

ImageOptim is a free, open source Mac app that makes JPEG, PNG, GIF and SVG files smaller. You drop a pile of images on it and it compresses them all, lossless by default, with an optional lossy mode. It also strips what you didn't mean to share: EXIF data like GPS and the camera's serial number, thumbnails, comments and colour profiles. It works from the Dock, the Services menu and the command line.

Two things to know. WebP isn't in its list of formats, and its page doesn't give a release date for the current version, 1.9.3, which added Apple silicon support. ImageOptim also sells a separate web API, from $12 a month for 2,000 optimizations, on its API pricing.

We make Koi, so read this with that in mind. Koi compresses images on your Mac and removes their metadata, but one picture at a time and not losslessly, so it doesn't replace ImageOptim for batches. That's why it isn't first below. Every fact about another app comes from its own site, checked October 21, 2026. We didn't run tests or benchmarks.

• WebP, AVIF or HEIC. ImageOptim lists JPEG, PNG, GIF and SVG only.
• A target size. You need a photo under 1 MB for a form, not just smaller.
• Resizing. Most oversized photos need fewer pixels, not better compression.
• Clipboard and screenshots. You want images shrunk as you copy or capture them.
• Updates. Its page shows no date for the last release.

1. Open the photo in Preview.
2. Choose Tools, Adjust Size. Turn on Resample image and lower the width, or the resolution. The resulting size shows at the bottom.
3. Click OK, then choose File, Export.
4. Pick JPEG, set a lower quality, and save the copy.

1. Start dragging the photo in Finder, on your desktop or from another app.
2. While you hold it, press Shift. The picture wheel opens round your pointer, its size in the middle.
3. Drop it on Compress. Pick Light, Balanced or Strong, or Compress to a file size and type, say, 500 KB.
4. Check the size before and after, and save. A copy like “Beach compressed.jpg” lands beside the original.

To strip location and camera data, drop it on Metadata instead and click Remove all. More on the Shift wheel, or step by step in how to use it.

From each app's own site. “Not listed” means the site doesn't say.

For a website's folder of PNGs, ImageOptim is the better tool: drop the folder, wait, done, with no quality lost, for free. Koi doesn't do that.

Koi is better for the one photo you need to send right now: under 2 MB for a form, without where it was taken, maybe cropped to a square or with a face blurred first. That's one drag and a few clicks, on your Mac. And Koi is more than images: the same drag works on videos, PDFs, Word files and archives, and Koi also types what you say with dictation and has an assistant that can see your screen.

Photos from an iPhone are often HEIC, which ImageOptim's page doesn't list. In Koi, Compress keeps a HEIC a HEIC, so it stays small on Apple devices. If the person you're sending it to is on Windows, or a web form only takes JPEG, drop it on Convert and click JPEG first, then compress the JPEG.

Optimage handles HEIC too, per its site. Whatever you use, check the photo's location: it travels with the file until something removes it. Koi's Metadata shows it with Show in Maps, and Remove all takes it out.

• Automatic, as you copy and capture, with WebP and AVIF? Clop.
• Batches with WebP, HEIC and resizing? Optimage.
• Free, one image, in the browser without uploading? Squoosh.
• One photo to a size, without its location, on your Mac? Koi.
• Quick and free, and uploading is fine? TinyPNG.

Also see Permute alternatives for converting formats, CleanShot X alternatives for screenshots, and Koi's plans.