Nous: Hermes 4 405B

nousresearch/hermes-4-405b

Released Aug 26, 2025131,072 context

$1/M input tokens$3/M output tokens

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 <think>...</think> traces or respond directly, offering flexibility between speed and depth. Users can control the reasoning behaviour with the reasoning enabled boolean. Learn more in our docs

The model is instruction-tuned with an expanded post-training corpus (~60B tokens) emphasizing reasoning traces, improving performance in math, code, STEM, and logical reasoning, while retaining broad assistant utility. It also supports structured outputs, including JSON mode, schema adherence, function calling, and tool use. Hermes 4 is trained for steerability, lower refusal rates, and alignment toward neutral, user-directed behavior.

Providers for Hermes 4 405B

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Performance for Hermes 4 405B

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Effective Pricing for Hermes 4 405B

Actual cost per million tokens across providers over the past hour

Apps using Hermes 4 405B

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Recent activity on Hermes 4 405B

Total usage per day on OpenRouter

Prompt

33.8M

Completion

1.54M

Reasoning

15K

Prompt tokens measure input size. Reasoning tokens show internal thinking before a response. Completion tokens reflect total output length.

Uptime stats for Hermes 4 405B

Uptime stats for Hermes 4 405B across all providers

Sample code and API for Hermes 4 405B

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Hermes 4 405B - API Pricing & Providers | OpenRouter