An ImageOptim alternative that also converts formats
ImageOptim is a much-loved free tool — but it was built for an era of PNG and JPEG. If you're dealing with iPhone HEIC photos, publishing WebP or AVIF for the web, or want bigger savings without digging through settings, TinyPresso may suit you better.
TinyPresso vs ImageOptim at a glance
| TinyPresso | ImageOptim | |
|---|---|---|
| Where it runs | On your Mac, offline | On your Mac, offline |
| Default mode | Smart compression — removes detail you can't see | Lossless (lossy is optional in settings) |
| Formats it shrinks | PNG, JPEG, HEIC, AVIF, WebP | PNG, JPEG, GIF, SVG |
| Convert to WebP / AVIF / HEIC | Yes, in the same drop | No |
| Price | Free to use; extended abilities via subscription or one-time purchase | Free, open source |
ImageOptim details from imageoptim.com, checked October 2026.
Why files get so much smaller
ImageOptim's default lossless mode keeps every pixel exactly the same and squeezes out wasted space in the file. That's safe, but the savings are usually modest. TinyPresso goes further by default: images store far more shades of color than your eyes can tell apart, so it quietly removes the invisible extras. The image looks the same; the file doesn't.
Some real results from our tests:
- Portrait photo PNG: 2.3 MB → 734 KB (−69%)
- Retina screenshot (2880×1800): 875 KB → 261 KB (−70%)
- Smooth gradient graphic: 124 KB → 20 KB (−84%)
Modern formats in the same step
Pick an output format and TinyPresso converts while it compresses. Turn a pile of PNG screenshots into WebP for a blog (our Retina screenshot shrank to 94 KB), or turn iPhone HEIC photos into JPEGs that open everywhere. No second app, no extra step.
When ImageOptim is still the right choice
If you need SVG or animated GIF optimization, want a strictly lossless result where no pixel may change, or prefer open-source software, ImageOptim remains excellent — and it's free. Plenty of people keep both: ImageOptim for SVGs, TinyPresso for photos, screenshots and format conversion.
Related
- The best image compressors for Mac in 2026
- TinyPNG alternative for Mac
- How to compress PNG files on a Mac
FAQ
Is there an ImageOptim alternative that supports WebP and AVIF?
Yes. TinyPresso compresses and converts PNG, JPEG, HEIC, AVIF and WebP on your Mac, so you can turn PNG or JPEG files into WebP or AVIF in the same step.
Is TinyPresso lossless like ImageOptim?
Not by default. TinyPresso removes color detail your eyes can't tell apart, which makes files much smaller while they look the same. If you need every pixel unchanged, ImageOptim's lossless mode is the better fit.
Does TinyPresso upload my images?
No. Like ImageOptim, TinyPresso works entirely on your Mac and never uploads your images.
TinyPresso compresses and converts images right on your Mac — free to use, 100% offline.
Download for Mac