# nix-build > Build a Nix expression. > See also: `nix3 build`. > More information: <https://nixos.org/manual/nix/stable/command-ref/nix-build.html>. - Build a Nix expression: `nix-build '<nixpkgs>' --attr {{firefox}}` - Build a sandboxed Nix expression (on non-NixOS): `nix-build '<nixpkgs>' --attr {{firefox}} --option sandbox true`