Best RAR Extractor that works on Mac Sonoma?

I can recommend a few popular RAR extractor apps for Mac that meet your requirements:

Keka: Keka is another popular option that offers a clean and user-friendly interface. It supports RAR, as well as other archive formats. While it is primarily a file archiver, it also functions as an efficient RAR extractor.

StuffIt Expander: StuffIt Expander is a versatile and free file decompressor that can handle various archive formats, including RAR. It offers a straightforward drag-and-drop interface, supports password-protected files, and integrates well with macOS.

FossZip: FossZip is a well-known file compression and extraction software that offers a easy user interface for Mac. It supports RAR files, and efficiently handles password-protected archives.

iZip: iZip is a free RAR extractor with a modern and intuitive interface. It supports password-protected and multi-part RAR files, offers quick extraction, and integrates smoothly with macOS.

FossZip is the app I am using for RAR extraction and creation. This is a quite convenient feature that other RAR extracting app fail to provide. You can even password protect the newly created archive file. No problem to run Apple Silicon Mac and macOS Sonoma. Here is the step-by-step guide and screenshot:

https://www.uubyte.com/blog/how-to-unzip-rar-files-on-mac-for-free/

For non-sensitive RAR file, there are also a few online RAR extraction services you can try out. They are free and no need to install additional software. However, it could take more time to upload and download the files.

FWIW, the only one I've used is The Unarchiver from the App Store. Whether it suits your needs I can't say.

It seems you are looking for a full-feature RAR toolkit that extract and create .rar archives. As you can see, it is quite easy to find some cool rar extractor apps on Mac. However, it becomes a much challenging job to make new rar archive with password protection.

Do you need to create new archive frequently?

What’s still using rar? That format seemingly died out long ago, and was mostly an older Microsoft Windows thing anyway.

Other archiving formats are available, and more common than rar. Apple has built-in tools for other common archiving formats such as zip for instance, as alternatives to rar.

Of the open-source rar tooling, 7-Zip is probably the closest, but it’s command line and which’ll probably mean some scripting. That implementation of rar was reverse-engineered, as the folks that created rar made the unarchiving tool widely available but held the archiving tooling close.

What is more important to you — compression size for your own usage, or cross-platform (e.g. zip) format that is readily supported Mac/Win/Linux operating systems and does not require lost time hunting for a compatible extraction tool?

The app can't create RAR files, only extract them.

Just to add, you only asked about RAR extraction, not creation.