Artificial Analysis publishes evaluation results for Reflection's first model, Beam

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Reflection AI open-sources Beam-1.0-501B-A23B, ranked 12th on the Agent Arena open-source leaderboard

Reflection AI has released the open-source model Beam-1.0-501B-A23B under the Apache 2.0 license. It ranks 12th among open-weight models on Agent Arena with a Net Improvement of -3.67%, and ranks 22nd on the Code Arena: WebDev open-source leaderboard with a score of 1438. On the Agent Arena leaderboard it is the highest-ranked US open-source model, ahead of Hy3, MiMo V2.5 Pro and MiniMax M3, but its Net Improvement error margin reaches ±3.84%, making it statistically closer to the two Qwen3.8 models above it. Of the top 25 open-source models on Code Arena: WebDev, 24 come from Chinese labs; Beam 1.0 is the only exception and the highest-ranked US open-source model on that leaderboard, slightly ahead of Kimi K2.5 Thinking and GLM-5.

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Reflection Releases Its First Model Beam, Scoring 30 on the Artificial Analysis Intelligence Index

Reflection has released its first model, Beam, an open-weight model with 501B total parameters and 23B activated parameters. It scores 30 on the Artificial Analysis Intelligence Index, ranking second among US open-weight models, behind only Meta's Muse Spark Open (39) and ahead of NVIDIA's Nemotron 3.5 Super VL (26). Beam consumes about 26k output tokens per Intelligence Index task, of which about 19k are used for reasoning and 7k for answering; it scores 48.5% on AutomationBench-AA, but only 3.0% on Terminal-Bench 4.0. On AA-Omniscience, it answers 33% of questions correctly, with a hallucination rate of 47% and a net index score of 1.5.