--- title: Hermes 3 405B Instruct — Free LLM | ModelsLab description: Access Nous: Hermes 3 405B Instruct (free) via API for advanced reasoning and code generation. Try this 405B parameter model now. url: https://modelslab.com/nous-hermes-3-405b-instruct-free canonical: https://modelslab.com/nous-hermes-3-405b-instruct-free type: website component: Seo/ModelPage generated_at: 2026-06-03T17:42:17.267314Z --- Available now on ModelsLab · Language Model Nous: Hermes 3 405B Instruct (free) Frontier LLM Free --- [Try Nous: Hermes 3 405B Instruct (free)](/models/open_router/nousresearch-hermes-3-llama-3.1-405b-free) [API Documentation](https://docs.modelslab.com) Unlock Hermes Capabilities --- Agentic Power ### Advanced Reasoning Control Steer 405B model for reasoning, roleplay, and multi-turn chats with precise prompt adherence. Code Mastery ### Superior Generation Generate, debug, and optimize code across languages using Nous: Hermes 3 405B Instruct (free). Long Context ### 131K Token Window Maintain coherence in extended conversations with Nous: Hermes 3 405B Instruct (free) API. Examples See what Nous: Hermes 3 405B Instruct (free) can create --- Copy any prompt below and try it yourself in the [playground](/models/open_router/nousresearch-hermes-3-llama-3.1-405b-free). Code Debugger “Analyze this Python function for bugs and suggest optimizations: def fibonacci(n): if n <= 1: return n else: return fibonacci(n-1) + fibonacci(n-2)” Math Solver “Solve step-by-step: Find the integral of x^2 \* e^x dx using integration by parts.” JSON Formatter “Convert this data to structured JSON with schema validation: user data includes name, age 30, skills python rust.” Logic Puzzle “Three houses in a row. Red has fox, blue has dog, green has bird. Who lives next to the cat owner?” For Developers A few lines of code. Hermes 405B. Free API. --- ModelsLab handles the infrastructure: fast inference, auto-scaling, and a developer-friendly API. No GPU management needed. - **Serverless:** scales to zero, scales to millions - **Pay per token,** no minimums - **Python and JavaScript SDKs,** plus REST API [API Documentation ](https://docs.modelslab.com) PythonJavaScriptcURL Copy ```

import requests

response = requests.post(
    "https://modelslab.com/api/v7/llm/chat/completions",
    json={
  "key": "YOUR_API_KEY",
  "prompt": "",
  "model_id": ""
}
)
print(response.json())

``` FAQ Common questions about Nous: Hermes 3 405B Instruct (free) --- [Read the docs ](https://docs.modelslab.com) ### What is Nous: Hermes 3 405B Instruct (free)? Full fine-tune of Llama 3.1 405B by Nous Research. Focuses on user alignment, reasoning, and code. Free via API endpoints. ### How to use nous hermes 3 405b instruct free API? Include Puter.js library in JS or use OpenAI-compatible endpoints in Python/cURL. No backend setup needed. Supports max 16K output tokens. ### Nous: Hermes 3 405B Instruct (free) context length? 131,072 tokens input window. Handles long multi-turn conversations. Up to 16K tokens output per response. ### Is Nous: Hermes 3 405B Instruct (free) model good for coding? Excels in code generation, debugging, and explanations. Competitive with Llama 3.1 Instruct. Supports multiple languages. ### Nous: Hermes 3 405B Instruct (free) alternative to paid LLMs? Free access matches paid models in reasoning and steerability. Use via API for agentic tasks. Strong prompt adherence. ### Does nous hermes 3 405b instruct free support function calling? Yes, reliable function calling and structured output. Ideal for tool use and JSON responses. Works in JS frameworks. Ready to create? --- Start generating with Nous: Hermes 3 405B Instruct (free) on ModelsLab. [Try Nous: Hermes 3 405B Instruct (free)](/models/open_router/nousresearch-hermes-3-llama-3.1-405b-free) [API Documentation](https://docs.modelslab.com) --- *This markdown version is optimized for AI agents and LLMs.* **Links:** - [Website](https://modelslab.com) - [API Documentation](https://docs.modelslab.com) - [Blog](https://modelslab.com/blog) --- *Generated by ModelsLab - 2026-06-03*