1-Bit Bonsai Image 4B Image Generation for Local Devices

Anthropic has released Bonsai Image 4B, a family of compact image-generation models designed to run efficiently on local devices like laptops and iPhones. The models achieve this through weight quantization, converting the transformer weights to binary and ternary formats instead of full precision, reducing the 1-bit variant to just 3.42 GB on Apple Silicon—an 8.3x reduction from the original 7.75 GB full-precision model. This represents a new deployment approach for image generation with capable outputs, open weights, and practical local inference on previously unsupported devices.