Meta AI ↗Released July 23, 2024

Llama 3.1 405B

Open Source#9 Arena Rank405B parameters

Context

128K

Input

Free (open)

Key Specifications

🏆

Arena Rank

#9

📐

Context Window

128K

📥

Input Price

per 1M tokens

Free (open)

📤

Output Price

per 1M tokens

Free (open)

🧠

Parameters

405B

🔓

Open Source

Yes

Best For

Complex reasoningcodingmultilingual tasks

About Llama 3.1 405B

Llama 3.1 405B is Meta's largest and most capable open-source language model, representing a major milestone as the first open model to rival top proprietary systems like GPT-4 and Claude 3.5 Sonnet across many benchmarks. With 405 billion parameters and a 128K context window, it excels at complex reasoning, coding, multilingual translation, and tool use. Its open-weight nature has made it a foundation for the open-source AI ecosystem, enabling organizations to deploy frontier-level AI without vendor lock-in.

Built byMeta AI↗

Pricing per 1M tokens

Input Tokens

Free (open)

Output Tokens

Free (open)

Compare Llama 3.1 405B

See how Llama 3.1 405B stacks up against other leading AI models

Llama 3.1 405B vs Llama 3.2 90B VisionCompare →Llama 3.1 405B vs Llama 3.3 70BCompare →Llama 3.1 405B vs Llama 3.1 70BCompare →Llama 3.1 405B vs Llama 3.1 8BCompare →Llama 3.1 405B vs Llama 3 70BCompare →

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Frequently Asked Questions

What is Llama 3.1 405B?▾
Llama 3.1 405B is Meta's largest and most capable open-source language model, representing a major milestone as the first open model to rival top proprietary systems like GPT-4 and Claude 3.5 Sonnet across many benchmarks. With 405 billion parameters and a 128K context window, it excels at complex reasoning, coding, multilingual translation, and tool use. Its open-weight nature has made it a foundation for the open-source AI ecosystem, enabling organizations to deploy frontier-level AI without vendor lock-in.
How much does Llama 3.1 405B cost?▾
Llama 3.1 405B costs Free (open) per 1 million input tokens and Free (open) per 1 million output tokens. Pricing is based on token usage, making it cost-effective for both small and large-scale applications.
What is Llama 3.1 405B's context window?▾
Llama 3.1 405B has a context window of 128K tokens. This determines how much text the model can process in a single request — larger context windows allow the model to handle longer documents, maintain more conversation history, and reason over bigger codebases.
Is Llama 3.1 405B open source?▾
Yes, Llama 3.1 405B is open source. This means the model weights are publicly available, allowing developers and organizations to download, fine-tune, and self-host the model on their own infrastructure. Open-source models offer greater flexibility and data privacy control.
What is Llama 3.1 405B best for?▾
Llama 3.1 405B is best suited for: Complex reasoning, coding, multilingual tasks. These use cases leverage the model's specific strengths in terms of capability, speed, and cost-effectiveness within Meta AI's model lineup.