Help Center

Mass Image Compressor (MIC) is desktop software for batch image compression, resizing, format conversion and image watermarking. It is available for Windows and macOS.

Windows: Available through Sourceforge, Github, Microsoft Store.

macOS: Available on the Mac App Store.

Yes. The Windows version is available as free and open-source software. A paid Microsoft Store version is also available for users who prefer installation and updates through Microsoft Store.

The macOS version is free to download from the Mac App Store, with optional in-app purchases.

On Windows, the paid Microsoft Store version does not include any additional features. Purchasing it is simply a way to support the project while getting the app through Microsoft Store.

On macOS, some professional workflow features require an in-app purchase, including keyboard shortcuts, file selection filters, image watermarking, lossy PNG compression, advanced file renaming etc. The core features typically used by casual users remain free with no usage limits.

No. Mass Image Compressor does not collect or transmit information from your computer. Images and other files are processed locally on your device and are not uploaded to our servers.

Mass Image Compressor is available for Windows and macOS. Features and supported formats differ slightly between the two versions.

Supported Input: JPEG/JPG, PNG, WebP, GIF, TIFF/TIF, AVIF, HEIC, JP2, BMP, SVG, JXL, ARW, DNG, NEF, CR2, CR3, CRW, DCR, MRW, ORF, RAF, PEF, RAW, RW2, SRW, ERF, 3FR, KDC, MOS, MEF, PSD, PPM, PGM, PBM, PNM, PAM, XBM, XPM, MPO, J2K, JPC, JPF, JPM, JPX, MJ2, SVGZ, HDR, EXR, PFM, NRW, SR2, SRF, RWL, X3F, GPR, IIQ

Supported Output: JPEG, WebP, PNG, GIF, AVIF

Supported Input: JPEG/JPG, JP2, TIFF/TIF, GIF, PNG, BMP, HEIF, HEIC, WebP, CR2, CR3, NEF, ORF, ARW, RAF, RW2, DNG, PSD, SRW

Supported Output: JPEG, WebP, PNG, GIF, HEIC

Yes. Both versions support several camera RAW formats.

Windows supports formats including CR2, CR3, NEF, ARW, RAF, DNG, ORF, RW2 and many others. macOS supports CR2, CR3, NEF, ORF, ARW, RAF, RW2, DNG and SRW.

Yes. Both the Windows and macOS versions can convert supported input images to WebP. Mass Image Compressor intelligently choose lossless compression if that can result in smaller image size.

The Windows version supports AVIF output. AVIF output is not currently supported by the macOS version.

The macOS version supports HEIC output. HEIC is supported as an input format on Windows, but HEIC output is not currently provided by the Windows version.

Yes. MIC can process supported animated image formats and can convert between supported animated formats while retaining the animation.

MIC does not currently create a new animation from a collection of individual image frames.

Yes. MIC supports both lossless and lossy PNG optimization, making it useful for reducing the file size of screenshots and other PNG images.

No. Image processing is performed locally on your computer. Your images do not need to be uploaded to an online service for compression or conversion.

Yes. Batch image resizing is supported on both Windows and macOS.

Yes. MIC provides options to retain EXIF and other image metadata in output images.

Yes. Both Windows and macOS support image-based watermarking. You can choose watermark image that appears at bottom right corner in output image.

Yes. MIC provides a live preview so you can evaluate compression and quality settings before processing your images.

The macOS version supports video compression and resizing. Supported video inputs include MOV, QuickTime, MP4, M4V, 3GP/3GPP, 3GPP2 and MTS formats. Video output is MP4. It uses Apple’s hardware based encoder so compression is fast but file doesn’t reduce as much as slower software based encoders (like from ffmpeg).

The Windows version currently focuses on image processing and does not provide video compression.

No. Image cropping is not currently supported.

No. MIC is focused on compression, resizing, format conversion and watermarking rather than general photo editing.

MIC can resize images, including increasing their dimensions, but it does not currently provide AI-based or enhancement-based image upscaling.

Yes. A portable/no-install Windows build is available in addition to the normal installer. You can visit Windows page to get download link.

The Windows application is available free and open source. The Microsoft Store version provides another installation and update channel and gives users a way to financially support continued development.

The Windows version is open source. The macOS version is distributed through the Mac App Store and is not open source.

The core image compression, resizing, conversion and watermarking functionality is similar. UI also feels a lot similar. 

Some platform-specific differences include:

• Windows supports AVIF output.
• macOS supports HEIC output.
• macOS supports video compression and resizing.
• Windows offers a portable/no-install version.
• The Windows version is open source.

See the Windows and macOS pages for the current feature and format comparison.