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RAR Archives

BetterZip has unrar capabilities built in so it can open, list, and extract RAR archives out of the box. Creating, updating, and repairing RAR archives needs the external rar command-line tool, which BetterZip can download and install for you. BetterZip does not include a RAR license; you can purchase a license separately from win.rar GmbH.

Setting up the rar command-line tool

Open BetterZip > Settings > Helpers and click the Add RAR button. The External RAR Archiver window appears with three things you can do:

  • Download & Install RAR fetches the current build from win.rar GmbH and installs it in your Application Support folder. Choose Help > Open BetterZip’s App Support folder for a quick peek.
  • Keep up-to-date tells BetterZip to check periodically and install new versions automatically.
  • Path to the RAR program shows where the tool lives. If you already have rar installed somewhere, drop or type its path here instead of using the download button.

Once BetterZip knows the path to rar, the RAR format becomes available everywhere a save preset or save panel lets you choose a format. RAR archives can be password-encrypted and split into multiple volumes.

Recovery records and recovery volumes

The RAR format has two error-correction features that BetterZip can both create and consume:

Recovery records
Extra data embedded in a single archive that lets RAR repair small amounts of corruption.
Recovery volumes (.rev files)
Companion files for multi-volume RAR sets. Each .rev can replace one missing or damaged volume in the set.

Adding recovery to a new archive

Pick the rar format in a save preset or in the Save dialog. Two extra fields appear:

  • Recovery records: the size of the embedded recovery data, as a percentage of the archive. 1–3 % is typical; higher values give more protection at a storage cost.
  • Recovery volumes: how many .rev companion files to create, expressed as a percentage of the volume count. Only relevant once the archive is also split into multiple volumes. For a 10-part set, entering 20 % creates 2 .rev files – enough to recover any 2 missing or damaged parts.

Repairing a damaged archive

BetterZip uses the recovery data automatically when it finds damage:

  • Opening a damaged RAR: BetterZip prompts with a Repair button. Click it to let RAR rebuild the archive from its recovery records.
  • Opening a multi-volume set with the first part missing: if matching .rev files are alongside, BetterZip prompts with a Reconstruct button to rebuild the missing volumes from the recovery volumes.
  • Choosing File > Test Archive Integrity (⌘T): if the test fails on a RAR archive, the same Repair prompt appears.

When to bother

  • Backups stored on long-term media benefit from recovery records: bit rot doesn’t immediately destroy them.
  • Archives distributed via flaky channels (USB sticks, lossy downloads) are good candidates for both records and volumes.
  • Archives that live on reliable filesystems (cloud, modern SSDs) usually don’t need this overhead.