Settings – Helpers

The Helpers tab is where BetterZip exposes its external-tool plumbing: the JSON format definitions that describe how each archive format is detected and processed, and the path to the optional external RAR archiver.

The Helpers List

The main list shows every format definition BetterZip knows about. By default only your custom entries are visible: toggle Show built-in helpers to see the bundled definitions as well. Each row shows the format name, the file extensions it claims, and the tool or framework it relies on.

The + button opens an inline JSON editor sheet so you can paste or write a new definition. Double-click any row to edit its JSON. The – button removes a custom entry. Built-in definitions are read-only on disk but you can override their options by editing the row; Restore Defaults wipes those overrides and re-reads the bundled JSON.

Tags 1–999 are reserved for built-ins. User-added definitions are auto-assigned a tag of 1000 or higher.

For the full schema – classes, placeholders, factor tables, magic-bytes detection, multi-volume handling – see Custom Format Definitions and the format specification reference.

External RAR Archiver

RAR extraction is built into BetterZip; you don’t need any external tool to open .rar files. But the RAR format is proprietary, and creating rar archives requires the original RAR tool (and a license) from RARLAB. The Helpers tab is where you point BetterZip at it.

Install Path
The path to the rar command-line binary. Click Browse to locate it if you’ve already downloaded it.

Download & Install RAR
Fetches the current RAR release for your Mac architecture from RARLAB and installs it in BetterZip’s application support folder. This is the easiest way to get RAR creation working.

Keep up-to-date
Periodically checks RARLAB for a newer RAR build and updates the installed binary. Recommended if you rely on RAR creation; the tool is updated occasionally for bug fixes and new options.

For more details on RAR creation, including format-specific options like solid archives and recovery records, see RAR Archives.