SimplerEnv provides simulated evaluation environments for generalist robot manipulation policies, enabling scalable and reproducible benchmarking. It adapts real-world robot setups (Google Robot, WidowX+Bridge) into simulation using SAPIEN and ManiSkill2/3, supporting GPU-parallelized evaluation that runs 10-15x faster than CPU versions. The framework offers Visual Matching evaluation (overlaying real images on simulation) and Variant Aggregation (testing across environment variations) to assess policy robustness before real-world deployment.