Hermes 4 405B

About this model

NousResearch Hermes 4 405B is the flagship hybrid-mode reasoning model based on Meta's Llama-3.1-405B architecture. Trained on a massive ~60B token corpus with explicit <think> deliberation segments, it delivers frontier-level performance in math, code, STEM, logic, and creative tasks. Achieves SOTA on RefusalBench for helpful, uncensored responses aligned to user values. Supports advanced function calling, structured JSON outputs, and tool use with extreme steerability and reduced refusal rates.

Technical specifications

Capabilities

Input modalities

Output modalities

Reasoning

Hybrid Default off

Knowledge horizon