  We introduce Mitiq, a Python package for error mitigation on noisy quantum
computers. Error mitigation techniques can reduce the impact of noise on
near-term quantum computers with minimal overhead in quantum resources by
relying on a mixture of quantum sampling and classical post-processing
techniques. Mitiq is an extensible toolkit of different error mitigation
methods, including zero-noise extrapolation, probabilistic error cancellation,
and Clifford data regression. The library is designed to be compatible with
generic backends and interfaces with different quantum software frameworks. We
describe Mitiq using code snippets to demonstrate usage and discuss features
and contribution guidelines. We present several examples demonstrating error
mitigation on IBM and Rigetti superconducting quantum processors as well as on
noisy simulators.
