Jamba 1.5 Mini is the smaller model in AI21 Labs’ Jamba 1.5 family, released alongside Jamba 1.5 Large on August 22, 2024. It shares the same hybrid Transformer-Mamba mixture-of-experts architecture, scaled down to 52 billion total parameters with 12 billion active, and it keeps the same 256,000-token context window as its larger sibling. On the Arena Hard benchmark it scored 46.1, ahead of similarly sized models such as Claude 3 Haiku, Mixtral 8x22B, and Command R+. AI21 built it for latency-sensitive business use cases like function calling, structured JSON output, and grounded generation, and prices it at $0.20 per million input tokens and $0.40 per million output tokens through its API. Like Jamba 1.5 Large, it’s released under AI21’s Jamba Open Model License with weights on Hugging Face and availability on AWS Bedrock.