Plain-English Summary
One of Meta’s largest open-weight dense language models for advanced text generation and research.
Llama 3.1 405B Instruct
One of Meta’s largest open-weight dense language models for advanced text generation and research.
Llama 3.1
General LLM
Open weights
Open weights: Yes
API: Via Meta and partners
Technical Notes
405B dense instruction model with 128K context, multilingual capability, and strong general reasoning.
Best For
Research, synthetic data, distillation, high-end self-hosted inference
Watch Out For
Extremely demanding to host and older than Llama 4.
Model Specs
- Maker
- Meta
- Country
- USA
- Family
- Llama 3.1
- Type
- General LLM
- Release date
- 2024-07-23
- Date confidence
- Exact
- Status
- Open weights
- Context window
- 131,072 tokens
- Max output
- Not listed
- Parameters
- 405B
- Active parameters
- 405B
- Architecture
- Dense transformer
- Reasoning
- General reasoning
- Tool calling
- Host dependent
- Structured output
- Host dependent
- API available
- Via Meta and partners
- Open weights
- Yes
- Self-hostable
- Yes
- License
- Llama 3.1 Community License
- Inputs
- Text
- Outputs
- Text
- Approx. price
- See provider pricing
- How to access
- Provider website
- Model / API ID
- Llama-3.1-405B-Instruct
- Knowledge cutoff
- Not publicly disclosed
- Fine-tuning
- Fine-tuning, distillation, self-hosting
- Completeness
- 95 %
- Verified
- Jul 18, 2026
- Snapshot date
- Jul 18, 2026
- Source
- Official source