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Meta AIReleased July 23, 2024

Llama 3.1 405B

Open Source#9 Arena Rank405B parameters

Llama 3.1 405B ranks in the top 10 on the Arena leaderboard. Context window: 0.128K tokens.

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, developed by Meta AI, is the largest open-source language model with 405 billion parameters and a 128K token context window. The model rivaled GPT-4-class performance on many benchmarks at the time of its release, representing one of the most ambitious open-source AI projects in history. Training required massive computational resources, but Meta open-sourced all weights, enabling the global research community to study, fine-tune, and deploy it freely. Llama 3.1 405B requires multiple high-end GPUs for inference, limiting deployment to organizations with substantial compute infrastructure. It supports multilingual tasks, advanced reasoning, and tool use. Llama 3.1 405B ranks #9 on the Chatbot Arena leaderboard, confirming that open-source models can compete at the frontier of AI capability when sufficient resources are invested in training.

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 8BCompare →

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Frequently Asked Questions

What is Llama 3.1 405B?▾
Llama 3.1 405B, developed by Meta AI, is the largest open-source language model with 405 billion parameters and a 128K token context window. The model rivaled GPT-4-class performance on many benchmarks at the time of its release, representing one of the most ambitious open-source AI projects in history. Training required massive computational resources, but Meta open-sourced all weights, enabling the global research community to study, fine-tune, and deploy it freely. Llama 3.1 405B requires multiple high-end GPUs for inference, limiting deployment to organizations with substantial compute infrastructure. It supports multilingual tasks, advanced reasoning, and tool use. Llama 3.1 405B ranks #9 on the Chatbot Arena leaderboard, confirming that open-source models can compete at the frontier of AI capability when sufficient resources are invested in training.
How much does Llama 3.1 405B cost?▾
Meta AI charges Free (open) per 1M input tokens for Llama 3.1 405B, with output at Free (open). Competitive with other models in its tier.
What is Llama 3.1 405B's context window?▾
Llama 3.1 405B supports up to 128K tokens per request. A larger context window allows the model to reason over longer inputs, which matters for document analysis, code review, and multi-turn conversations.
Is Llama 3.1 405B open source?▾
Yes — Meta AI released Llama 3.1 405B as open source. That means you're free to deploy it however you want: cloud, on-prem, edge. No API lock-in.
What is Llama 3.1 405B best for?▾
Meta AI positions Llama 3.1 405B for: Complex reasoning, coding, multilingual tasks. Real-world performance will depend on your specific prompts and data, but these are the intended strengths.