Meta: Llama 3.1 405B Instruct
Llama 3.1 405B Instruct is Meta's largest open-weight model from mid-2024 with a 131K context window and tool use support, but it has no benchmark data in this listing; at $4/1M tokens it sits in a competitive price band where benchmarked alternatives offer more certainty.
Assessment date: March 12, 2026
Our methodology takes into account a range of factors including pricing, functionality, capabilities, benchmark performance, and real-world applicability. Rankings are reviewed and updated regularly as new models are released. Issues with our rankings? Contact us
The highly anticipated 400B class of Llama3 is here! Clocking in at 128k context with impressive eval scores, the Meta AI team continues to push the frontier of open-source LLMs. Meta's latest class of model (Llama 3.1) launched with a variety of sizes & flavors. This 405B instruct-tuned version is optimized for high quality dialogue usecases. It has demonstrated strong performance compared to leading closed-source models including GPT-4o and Claude 3.5 Sonnet in evaluations. Usage of this model is subject to Meta's Acceptable Use Policy.
Architecture
| Modality | Text → Text |
| Tokenizer | Llama3 |
| Instruct Type | llama3 |
| Parameters | 405B |
Model Information
Pricing
| Token Type | Cost per 1M tokens | Cost per 1K tokens |
|---|---|---|
| Input | $4.00 | $0.004000 |
| Output | $4.00 | $0.004000 |
External Resources
Data sourced from OpenRouter API, Artificial Analysis and Hugging Face Open LLM Leaderboard. Scores are editorially curated by our team.
Last updated: March 13, 2026 7:52 pm