Make images lighter without degrading visual quality.
OIMG uses modern image compression techniques to reduce file size.
brew install --cask oimg
Open effortlessly
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Remain in control
OIMG provides you with Pixel Match Percentage, MS-SSIM, and SSIMULACRA 2 in real time — so you can proactively set optimization thresholds, instead of worrying about unexpected quality drops.
← →
Original
Optimized
Navigate trade-offs
Compare outcomes before you commit. OIMG keeps the quality, size, and format trade-offs visible while you tune the export.
Compatibility? No problem.
Convert back to JPG or PNG on demand with one click—for example, when uploading onto websites that only support limited formats!

Free and Open Source
OIMG is free for personal and academic use forever, and is open sourced under GPLv3 license. Please contact license@oimg.org to discuss custom license arrangements.