Run Commands Under Rosetta with arch

Execute any command as an Intel binary on an Apple Silicon Mac.

macOSdeveloperarchrosettaLow risk

Run `arch -x86_64 /usr/local/bin/legacy-tool` to launch that tool through Rosetta.

01Command

Command

$ arch -x86_64 /usr/local/bin/legacy-tool

02What it does

Some older tools and x86-only packages still run only as Intel binaries. Prefixing a command with arch -x86_64 runs just that one command under Rosetta — no need to keep a separate 'Using Rosetta' Terminal open. Use `arch -arm64` for the reverse, and check a binary's architecture first with `file` or `lipo -info`.

03Risk

RiskLow risk

!Warning: Rosetta must be installed first (`softwareupdate --install-rosetta`); performance under Rosetta is lower than native arm64.

04Undo

✓No undo needed — this command does not change persistent state.

05Sources

arch(1) — execute a command under a different architecture
manpagez (arch(1) man page) · technical · 2026-09-17
Evidence: Documents arch -arch_name executing the given command with the specified architecture preference, e.g. -x86_64 under Rosetta.

Last verified: 2026-09-18 · Category: Developer