Preset Passmanagers (qiskit.transpiler.preset_passmanagers)

level_0_pass_manager(pass_manager_config)

Level 0 pass manager: no explicit optimization other than mapping to backend.

level_1_pass_manager(pass_manager_config)

Level 1 pass manager: light optimization by simple adjacent gate collapsing.

level_2_pass_manager(pass_manager_config)

Level 2 pass manager: medium optimization by initial layout selection and gate cancellation using commutativity rules.

level_3_pass_manager(pass_manager_config)

Level 3 pass manager: heavy optimization by noise adaptive qubit mapping and gate cancellation using commutativity rules and unitary synthesis.