Wanna compress a 6GB .ISO file to 4GB or less? Are you going to shrink an iSO image to fit on a CD with normal 700Mb? Calm down, here is the right place where easy yet effective solutions are shared for you to compress and downsize ISO image to fit on CD, hard drive, DVD and more on your Mac/Windows computer with the highest degree of image quality.
How to Compress ISO Image on MacBook/iMac
Here we recommend you top 2 ISO compressors: MacX DVD Ripper Pro and DVD Shrink.
1. MacX DVD Ripper Pro
The 5-star DVD ripper for Mac program from MacXDVD Software - MacX DVD Ripper Pro, is a strong performer to compress and shrink ISO image file size. It enables you to compress ISO image to MP4, MOV, MKV, AVI, FLV, and other digital formats with much smaller file size and 98% quality reserved. Still, its editing features (cut off the sidelights/segments; crop the unwanted video parts, etc.) enables you to downsize ISO file without lossing quality at all.
- Import ISO image by click Add DVD button.
- Choose the output format, resolution, size, etc.
- Click "RUN" to begin the ISO compression.

2. DVD Shrink
Another rising star in ISO shrinking field is the DVD Shrink, which is specially designed to compress ISO image without quality loss. It can shrink ISO image from DVD-9 to DVD 5, DVD-9 to 2xDVD-5, etc. with all data kept. This ISO video compressor is suitable for those who have high demand on video quality and lower demand on the output file size after the ISO compression.
- Press "Source" to load ISO image.
- Opt for "Full Copy" or "Main Movie".
- Click "Target" to choose storage path and hit "Next" to enter ISO shrinking process.

Compress ISO Image on Windows 10/8/7
1. UltraISO
UltraISO supports to compress ISO image to fit on CD, hard drive or DVD disc with new hard disk image (up to 16GB) and floppy image (up to 2GB). It also works perfectly as a ISO CD/DVD image file creating/editing/converting tool to directly edit CD/DVD image file on Windows.

2. ISO to USB
ISO to USB is a free yet useful tool for you to convert ISO image to USB drives. These USB drives include USB flash drives, memory sticks and other USB storage devices. It's also used to create a bootable USB disk on Windows operating system, including Windows 8/7/Vista/XP.

PSP ISO Compressor - Compress ISO to CSO
While googling, the first searching result is the PSP ISO compressor for game ISO files, which enables you to compress ISO to CSO, DAX, and the newly introduced JSO.
Beyond this, it allows you to convert DAX to CSO/JSO and convert JSO to DAX/CSO. Currently, it runs on Windows PC, the Mac version still on the way.
