Nousresearch: Nous: Hermes 4 405B

by Nousresearch Open Weight Reasoning

Hermes 4 is a large-scale reasoning model built on Meta-Llama-3.1-405B and released by Nous Research. It introduces a hybrid reasoning mode, where the model can choose to deliberate internally with...

Choose a model to compare against Nous: Hermes 4 405B

Specifications

Specifications for Nous: Hermes 4 405B
AttributeValue
Lab Nousresearch
Tags Open Weight Reasoning
Release Date 2025-08
Context Window 131,072 tokens
Input Price / 1M $1.00
Output Price / 1M $3.00
Input Modalities Text
Output Modalities Text

Strengths

  • Hybrid reasoning mode auto-decides when to think deeply
  • Strong instruction following and tool use
  • Open-weight on Llama 3.1 405B base
  • Uncensored no refusal for controversial topics

Weaknesses

  • Based on older Llama 3.1 architecture
  • Very large model slow and expensive to run
  • Less competitive on raw benchmarks vs latest models

Best For

  • Complex multi-step reasoning
  • Creative and uncensored writing
  • Research and experimentation
  • Tool-use and agentic workflows

In Depth: Nous: Hermes 4 405B

Summary

Nous: Hermes 4 405B is an AI model from Nousresearch.

Released 2025-08. It currently appears in the Overall category on LMRank. It supports Text input and produces Text output, with a context window of 131,072 tokens. Input pricing is $1.00 per 1M tokens and output is $3.00 per 1M tokens on OpenRouter.

Sources & Further Reading

Related Models