Compresso vs ImageOptim
Which should you use?
TL;DR: Pick Compresso if you want a simple Mac or Windows app that shrinks lots of photos and videos at once, writes to a separate output folder, and keeps internal folder structure on big jobs. Pick ImageOptim if you only use a Mac, only need images, and want unlimited free open-source optimization with no paid tier. ImageOptim does not compress video and does not run on Windows.
Key takeaways
| Tool | Best for | Key strength |
|---|---|---|
| Compresso | Mac and Windows users who compress lots of photos and videos offline | Bulk + folder jobs, separate output, images and video |
| ImageOptim | Mac-only users optimizing web images forever free | Unlimited free desktop image optimization with strong open-source tools |
ImageOptim is a long-running free Mac classic for web images. Compresso is a desktop bulk compressor for people who also need video, Windows, or a safer output-folder workflow. Here is a straight comparison.
Side-by-side comparison
| Compresso compresso.xyz | ImageOptim imageoptim.com | |
|---|---|---|
| Price | Free trial + $19-$39 lifetime | 100% free (GPL); donations welcome |
| Platforms | macOS, Windows desktop app | macOS only |
| Works offline (no upload) | Yes | Yes |
| Ease of use | 3 presets: quality, size, speed | Drag-drop; preferences for lossy tools |
| Compress images | JPG, PNG, WebP (+ HEIC on Mac) → JPG | JPEG, PNG, GIF, SVG + many optimizers |
| Compress videos | MP4, AVI, MOV, MPG, MPEG, MKV, WebM → MP4 | No |
| Batch in the UI | Up to 200 files (10 on free) | Drag-drop many images; no hard app quota |
| Compress a whole folder | Yes, up to 50GB; keeps internal folder structure | Drop folders; default is in-place optimize |
| Separate output folder (default) | Yes | No |
| Lossless by default | No | Yes |
| Open source | No | Yes |
| Dedicated support | Email support (priority for Pro) | Community / GitHub / docs |
Which platforms do they support?
ImageOptim is Mac only. That is the first filter for a lot of teams. If anyone on the project uses Windows, ImageOptim cannot be the shared tool.
Compresso runs on macOS and Windows with the same product idea: simple presets, bulk files, and folder jobs. There is no Linux build. For free offline image batching on Windows or Linux, see Compresso vs Caesium.
Which is better for bulk photo and video jobs?
Compresso Pro can take up to 200 files in one batch, or compress everything inside a folder up to 50GB. Nested subfolders stay nested in the output. Files that are already small enough get skipped automatically. Videos and images share the same app.
ImageOptim handles large image drops well and has no daily free quota, which is why Mac developers still love it. It does not compress video, and the default habit of optimizing in place is different from Compresso's separate output folder. Plan a backup or copy if you do not want originals replaced.
Lossless web tools vs simple presets
ImageOptim bundles known open-source tools (MozJPEG, pngquant, OxiPNG, SVGO, Zopfli, and more). It strips EXIF and other metadata by default and starts from a lossless path, with optional lossy tools in preferences. That fits people who care about web asset pipelines and exact formats.
Compresso exposes three plain-English controls: quality, size, and speed. Image output is JPG; video output is MP4. There is no AVIF encoder, no SVG optimizer, and no true lossless mode. If you only need a quick JPG in the browser without installing anything, use our free browser JPG compressor.
Price: free forever vs pay once
ImageOptim is free. You can use it every day with no session limits and no subscription. Donations help the project. On pure cash cost for Mac image work, ImageOptim wins.
Compresso lets you try 5 compressions free (up to 10 files or a 1GB folder each time). After that, pricing is $19 one-time for 1 device or $39 for 5 devices, with a 7-day money-back guarantee. You are paying for multi-platform bulk work, video support, and email support on Pro, not for unlocking basic image optimize on a single Mac.
Choose ImageOptim if…
- You only work on a Mac and only need images.
- You want unlimited free optimization with no paid tier.
- You care about open-source tools (MozJPEG, pngquant, OxiPNG, SVGO) and optional lossless-first workflows.
- You are fine optimizing files in place after you understand that default.
- You do not need video compression in the same app.
Choose Compresso if…
- You use Windows, or both Mac and Windows.
- You compress lots of files at once: up to 200 per batch, or a whole folder up to 50GB on Pro.
- You need videos as well as photos, with three presets (quality, size, speed).
- You want a separate output folder and folder structure kept in the result, with already-small files skipped.
- You want a lifetime license and email support instead of a free-only Mac tool.
Switching from ImageOptim to Compresso
Nothing cloud-based transfers. Install Compresso on Mac or Windows, point it at the same project folders, and check that you like the JPG/MP4 outputs. You will not get ImageOptim's SVG pipeline or lossless-first defaults inside Compresso.
Plan on about 10 minutes to try the free Compresso trial on a real folder. Keep ImageOptim for free Mac-only web asset cleanup if that is still your daily loop. For browser codec experiments, see Compresso vs Squoosh. For free multi-OS desktop images, see Compresso vs Caesium. More Mac offline options are also covered in best offline image compressor for Mac.
Frequently asked questions
Basics
Is Compresso an ImageOptim alternative?
Yes, if you want a simple Mac or Windows app that compresses many photos and videos at once, with a separate output folder. ImageOptim is still the better pick if you only use a Mac, only need images, and want unlimited free open-source optimization forever.
Is ImageOptim free?
Yes. ImageOptim is free and open source (GPL). Donations are encouraged. Compresso has a free trial (5 compressions), then a one-time lifetime license starting at $19.
Does ImageOptim work on Windows?
No. ImageOptim is Mac only. Compresso runs on macOS and Windows. If you need free offline image batching on Windows, see also Compresso vs Caesium.
Features & workflow
Does ImageOptim compress videos?
No. ImageOptim is an image optimizer. Compresso compresses both images (JPG, PNG, WebP, plus HEIC on Mac) and videos in the same app.
Does ImageOptim overwrite my original files?
By default ImageOptim optimizes files in place, which can surprise first-time users who expected a separate copy. Compresso writes to a separate output folder (Downloads/Compresso in files mode, or a sibling folder_compressed folder in folder mode).
Which is better for Mac web developers?
ImageOptim, if you only optimize web assets offline on a Mac and want free unlimited runs with tools like MozJPEG, pngquant, OxiPNG, and SVGO. Compresso, if you also need video, Windows machines, plain-English presets, or a mirrored folder of originals kept intact.
Is ImageOptim lossless?
ImageOptim is lossless by default and can optionally run lossy minification in preferences. Compresso uses perceptual/lossy compression (images out as JPG, videos as MP4) and has no true lossless mode.
Pricing
How much does Compresso cost compared to ImageOptim?
ImageOptim costs $0 forever. Compresso is $19 one-time for 1 device or $39 for 5 devices (lifetime), with a 7-day money-back guarantee and email support on paid plans.
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Last updated July 2026. ImageOptim details based on imageoptim.com/mac and github.com/ImageOptim/ImageOptim (~9.9k stars, GPL). If something is out of date, let us know.