Reflection releases open-weight model Beam

AI company Reflection released its first free, open model, Beam, targeting coding, logical reasoning, and agent tasks. It uses a mixture-of-experts architecture, activating 23 billion of its 501 billion total parameters per token.

Reflection released Beam, a text-only mixture-of-experts model for coding, agents, and scientific work. It has 501B total parameters and 23B active parameters, was trained from scratch, and will release all weights under Apache 2.0 later this month.

Reflection AI officially released its first frontier open-weight model, Beam, saying it performs comparably to leading Chinese open models on advanced reasoning benchmarks with 3–4 times less inference compute. Beam is a 501-billion-parameter, 23-billion-active-parameter text model, pretrained on 23.8 trillion tokens with a 1-million-token context window. The company says it matches Z.ai's GLM-5.2 and exceeds current leading Western open models.