What is ImageOptim?
ImageOptim is a Mac app that runs a set of open-source image optimisers over your files and keeps the smallest result, so images get smaller without a visible change in quality. It also removes invisible metadata by default: EXIF camera data, GPS position, embedded thumbnails, comments and colour profiles, with an option to keep them. It is free and open source under the GPL v2 or later, which is unusual among Mac image tools. The current release, 1.9.3, requires macOS 10.15 Catalina or newer and added support for Apple Silicon CPUs. It suits anyone shipping images to the web or bundling them into a Mac or iOS app, where every kilobyte is paid for twice.
Verified product facts
- Type
- image compression toolEditorially reviewed
- Platform
- macOS
- Apple Silicon
- Yes
- Pricing
- Open sourceDeveloper-stated
- Open source
- Yes
- Developer
- Kornel LesińskiDeveloper-stated
- Relationship to Nuanyue
- Third-party product — not published by NuanyueEditorially reviewed
- Licence
- GPL-2.0-or-later
- Current version
- 1.9.3Developer-stated
- Official website
- imageoptim.com/mac
Last updated . Facts marked developer-stated come from the developer and are not independently confirmed; editorially reviewed marks a Nuanyue judgement.
Key features
What ImageOptim does at a glance.
Lossless compression of PNG, JPEG, GIF and SVG by combining several open-source optimisers
Removes EXIF metadata, embedded thumbnails, comments and colour profiles
Optional lossy minification
For JPEG, PNG, GIF and SVG
Drag-and-drop
With files optimised in place and originals moved to the Trash
Finder Services, Apple Mail Markup and Dock icon integration
Command-line launch
For scripts and build systems
What you can use ImageOptim for
- Preparing images for the web before upload
- Removing EXIF and GPS data from photos before sharing them
- Shrinking image assets bundled into a Mac or iOS app
- Optimising a directory of images from a build script
Who is ImageOptim for?
- Anyone shipping images to the web, where file size and metadata matter
- Developers who want image optimisation inside a build script
- Photographers who want to remove GPS and camera metadata before publishing
Who is ImageOptim not for?
- Windows or Linux users — ImageOptim is macOS only
- Macs running macOS 10.14 or earlier — the current 1.9.3 requires macOS 10.15 Catalina
- People who want to edit images — ImageOptim compresses them rather than editing them
Limitations
- The developer's changelog lists no release dates, so the recorded date comes from the download file's timestamp
Strengths and trade-offs
What ImageOptim does well, and what to weigh before choosing it. Points marked developer-stated come from the developer’s own material and have not been independently confirmed.
Strengths
- Combines several open-source optimisers and keeps the smallest result for each file.Developer-stated
- Free and open source under the GPL v2 or later, with no paid tier.
- Removes EXIF metadata such as GPS position and camera serial number by default, with an option to keep it.Developer-stated
Trade-offs
- Requires macOS 10.15 Catalina or newer; 1.8.8 is the last version that supports macOS 10.14.
- Metadata removal is all-or-nothing: there is no option to strip only some kinds of metadata.
First-use experience
What the app asks of you when you set it up. Only established facts appear here; anything we could not confirm is left out rather than guessed at.
- Installation
- Download ImageOptim.tbz2 from imageoptim.com, open the archive and drag ImageOptim.app to Applications.
- First launch
- Drag images onto the window; files are optimised in place and the originals are moved to the Trash.
- System integration Developer-stated
- Adds a Finder Services entry, can be invoked from Apple Mail's Markup menu or the Dock icon, and ships a command-line entry point.
- Apple Silicon
- Supported
What it does
ImageOptim is a Mac app that wraps a set of open-source image optimisers and runs them over your files, keeping whichever produces the smallest result. It is a GUI for tools you would otherwise run one by one from a terminal, and it works by drag-and-drop: files are optimised in place, with the originals moved to the Trash.
How it optimises
Rather than relying on a single encoder, ImageOptim combines several and picks the best output per file. The set includes MozJPEG, pngquant, Pngcrush, AdvPNG, OxiPNG, SVGO, svgcleaner, Guetzli, Gifsicle, jpegoptim and jpegtran, with Zopfli for dense deflate streams.
By default it is lossless and preserves image quality exactly. Enabling Lossy minification in Preferences allows more aggressive settings, and the developer notes that lossy mode applies not only to JPEG but to PNG, animated GIF and SVG as well.
Metadata and EXIF
Images carry metadata that browsers ignore but that costs bytes and can leak private information: EXIF camera data, GPS position, the camera’s serial number, embedded thumbnails, comments and colour profiles. ImageOptim removes all of it by default, and an option in Preferences keeps it instead.
The limitation is granularity: it is all or nothing. There is no way to strip only some kinds of metadata while keeping others.
Command line and automation
ImageOptim can be driven from a shell in two ways. open -a ImageOptim .
launches it with the UI visible and optimises the current directory
asynchronously. For scripts and build systems, calling the binary directly
blocks until the work is done:
/Applications/ImageOptim.app/Contents/MacOS/ImageOptim *.pngThe app also exposes a Finder Services entry and can be invoked from Apple Mail’s Markup menu, and there is a third-party ImageOptim-CLI wrapper for finer control.
Versions and system requirements
The current release is 1.9.3, which requires macOS 10.15 Catalina or newer. Version 1.8.8 is the last release that supports macOS 10.14. The changelog on imageoptim.com lists no release dates, so the date recorded above comes from the timestamp on the developer’s own download file.
Apple Silicon
Recorded as supported. The 1.9.3 changelog lists “Support for Apple Silicon CPUs” among that release’s changes, which is the first-party statement the field rests on.
Release history
Dated releases recorded for ImageOptim, newest first, each with the source it was read from.
1.9.3Derived
Current release: adds support for Apple Silicon CPUs and requires macOS 10.15 Catalina or newer. The date is the download artifact's timestamp, since the changelog lists no dates.
Source: Official website
Questions about ImageOptim
Is ImageOptim free?
Yes. It is free and open source under the GPL v2 or later, with no paid tier.
Does ImageOptim run on Apple Silicon Macs?
Yes. The 1.9.3 changelog lists support for Apple Silicon CPUs among that release's changes.
What macOS version does ImageOptim need?
1.9.3 requires macOS 10.15 Catalina or newer. Version 1.8.8 is the last release that supports macOS 10.14.
Does ImageOptim remove EXIF and GPS data?
Yes, by default. It strips EXIF metadata, embedded thumbnails, comments and colour profiles. Stripping can be turned off in Preferences, but it is all-or-nothing — there is no way to remove only some kinds of metadata.
Can ImageOptim be run from the command line?
Yes. open -a ImageOptim . optimises a directory asynchronously with the UI visible, and the binary at /Applications/ImageOptim.app/Contents/MacOS/ImageOptim runs synchronously for scripts and build systems.
Competitors
Direct competitors: overlapping features aimed at the same users.
JPEGmini
Patented JPEG recompressor for Mac, free for 50 images a day.
Both shrink JPEG files on macOS, but JPEGmini is a closed-source commercial tool while ImageOptim is free and open source.
Compared with
Head-to-head comparisons Nuanyue has published.
Zipic
Batch image compression tool with presets and automation.
Both compress images on macOS; the two are compared head to head on Nuanyue.
Similar apps
Related in purpose, but not a straight swap.
ImageAlpha
Compress images with PNG format and remove transparency.
ImageAlpha comes from the same developer and targets PNG specifically, adding lossy PNG8 conversion where ImageOptim is lossless by default.
Works well with
Not a replacement — apps commonly used alongside this one.
Acorn
Mac image editor with non-destructive filters, sold outright.
Acorn edits images and ImageOptim shrinks the export, so the two are used one after the other in an image workflow.
Links
Sources
Facts on this page are checked against the sources below. Last updated .
