Older versions of WinRAR or other tools like The Unarchiver for Mac might struggle to open RAR5 archives if they aren't updated. Don't Use ZIP, Use RAR - Coding Horror

Select RAR (specifically RAR5 if available) for the best results, as it typically outperforms legacy RAR4 or ZIP.

Below is a write-up on how to configure these settings for maximum efficiency. Best Settings for Maximum RAR Compression

If you're looking for the best settings to achieve a (the smallest possible file size) when compressing data, the process involves maximizing WinRAR's compression algorithms.

A larger dictionary allows the software to find more patterns across the data. For high-performance PCs, 128 MB is recommended; otherwise, 32 MB is a solid standard. Archiving Options:

Set this to Best . This tells the software to prioritize file size over speed.

Selecting the "Best" compression method and a large dictionary size will make the compression process significantly slower .