Llama 3.1 405B vs Llama 3.1 70B Instruct
Llama 3.1 405B (2024) and Llama 3.1 70B Instruct (2024) are compact production models from AI at Meta. Llama 3.1 405B ships a 128K-token context window, while Llama 3.1 70B Instruct ships a 128K-token context window. On HumanEval, Llama 3.1 405B leads by 4.9 pts. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit. It focuses on practical selection signals rather than broad model-family marketing.
Llama 3.1 405B is safer overall; choose Llama 3.1 70B Instruct when provider fit matters.
Specs
| Specification | ||
|---|---|---|
| Released | 2024-07-23 | 2024-07-23 |
| Context window | 128K | 128K |
| Parameters | 405B | 70B |
| Architecture | decoder only | decoder only |
| License | Open Source | Open Source |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | Llama 3.1 405B | Llama 3.1 70B Instruct |
|---|---|---|
| Input price | - | $0.4/1M tokens |
| Output price | - | $0.4/1M tokens |
| Providers | - |
Capabilities
| Capability | Llama 3.1 405B | Llama 3.1 70B Instruct |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | No | No |
| Function calling | No | No |
| Tool use | No | No |
| Structured outputs | No | Yes |
| Code execution | No | No |
Benchmarks
| Benchmark | Llama 3.1 405B | Llama 3.1 70B Instruct |
|---|---|---|
| HumanEval | 89.0 | 84.1 |
| Massive Multitask Language Understanding | 88.6 | 86.0 |
| HellaSwag | 95.8 | 94.2 |
Deep dive
On shared benchmark coverage, HumanEval has Llama 3.1 405B at 89 and Llama 3.1 70B Instruct at 84.1, with Llama 3.1 405B ahead by 4.9 points; Massive Multitask Language Understanding has Llama 3.1 405B at 88.6 and Llama 3.1 70B Instruct at 86, with Llama 3.1 405B ahead by 2.6 points; HellaSwag has Llama 3.1 405B at 95.8 and Llama 3.1 70B Instruct at 94.2, with Llama 3.1 405B ahead by 1.6 points. The largest visible gap is 4.9 points on HumanEval, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on structured outputs: Llama 3.1 70B Instruct. Both models share the core language-model surface, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
Pricing coverage is uneven: Llama 3.1 405B has no token price sourced yet and Llama 3.1 70B Instruct has $0.4/1M input tokens. Provider availability is 0 tracked routes versus 11. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose Llama 3.1 405B when provider fit are central to the workload. Choose Llama 3.1 70B Instruct when provider fit and broader provider choice are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, Llama 3.1 405B or Llama 3.1 70B Instruct?
Llama 3.1 405B supports 128K tokens, while Llama 3.1 70B Instruct supports 128K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Is Llama 3.1 405B or Llama 3.1 70B Instruct open source?
Llama 3.1 405B is listed under Open Source. Llama 3.1 70B Instruct is listed under Open Source. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for structured outputs, Llama 3.1 405B or Llama 3.1 70B Instruct?
Llama 3.1 70B Instruct has the clearer documented structured outputs signal in this comparison. If structured outputs is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run Llama 3.1 405B and Llama 3.1 70B Instruct?
Llama 3.1 405B is available on the tracked providers still being sourced. Llama 3.1 70B Instruct is available on OctoAI API (Deprecated), Together AI, Fireworks AI, NVIDIA NIM, and Microsoft Foundry. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
When should I pick Llama 3.1 405B over Llama 3.1 70B Instruct?
Llama 3.1 405B is safer overall; choose Llama 3.1 70B Instruct when provider fit matters. If your workload also depends on provider fit, start with Llama 3.1 405B; if it depends on provider fit, run the same evaluation with Llama 3.1 70B Instruct.
Continue comparing
Last reviewed: 2026-05-11. Data sourced from public model cards and provider documentation.