Llama 3 8B Instruct vs Llama 3.1 405B
Llama 3 8B Instruct (2024) and Llama 3.1 405B (2024) are compact production models from AI at Meta. Llama 3 8B Instruct ships a 8K-token context window, while Llama 3.1 405B ships a 128K-token context window. On Google-Proof Q&A, Llama 3.1 405B leads by 6.7 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 fits 16x more tokens; pick it for long-context work and Llama 3 8B Instruct for tighter calls.
Specs
| Specification | ||
|---|---|---|
| Released | 2024-04-18 | 2024-07-23 |
| Context window | 8K | 128K |
| Parameters | 8B | 405B |
| Architecture | decoder only | decoder only |
| License | Open Source | Open Source |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | Llama 3 8B Instruct | Llama 3.1 405B |
|---|---|---|
| Input price | $0.03/1M tokens | - |
| Output price | $0.04/1M tokens | - |
| Providers | - |
Capabilities
| Capability | Llama 3 8B Instruct | Llama 3.1 405B |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | No | No |
| Function calling | No | No |
| Tool use | No | No |
| Structured outputs | Yes | No |
| Code execution | No | No |
Benchmarks
| Benchmark | Llama 3 8B Instruct | Llama 3.1 405B |
|---|---|---|
| Google-Proof Q&A | 44.8 | 51.5 |
| HumanEval | 68.2 | 89.0 |
| Massive Multitask Language Understanding | 76.9 | 88.6 |
| HellaSwag | 91.1 | 95.8 |
Deep dive
On shared benchmark coverage, Google-Proof Q&A has Llama 3 8B Instruct at 44.8 and Llama 3.1 405B at 51.5, with Llama 3.1 405B ahead by 6.7 points; HumanEval has Llama 3 8B Instruct at 68.2 and Llama 3.1 405B at 89, with Llama 3.1 405B ahead by 20.8 points; Massive Multitask Language Understanding has Llama 3 8B Instruct at 76.9 and Llama 3.1 405B at 88.6, with Llama 3.1 405B ahead by 11.7 points. The largest visible gap is 20.8 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 8B 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 8B Instruct has $0.03/1M input tokens and Llama 3.1 405B has no token price sourced yet. Provider availability is 16 tracked routes versus 0. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose Llama 3 8B Instruct when provider fit and broader provider choice are central to the workload. Choose Llama 3.1 405B when long-context analysis and larger context windows 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 8B Instruct or Llama 3.1 405B?
Llama 3.1 405B supports 128K tokens, while Llama 3 8B Instruct supports 8K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Is Llama 3 8B Instruct or Llama 3.1 405B open source?
Llama 3 8B Instruct is listed under Open Source. Llama 3.1 405B 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 8B Instruct or Llama 3.1 405B?
Llama 3 8B 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 8B Instruct and Llama 3.1 405B?
Llama 3 8B Instruct is available on AWS Bedrock, DeepInfra, OctoAI API (Deprecated), Fireworks AI, and Alibaba Cloud PAI-EAS. Llama 3.1 405B is available on the tracked providers still being sourced. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
When should I pick Llama 3 8B Instruct over Llama 3.1 405B?
Llama 3.1 405B fits 16x more tokens; pick it for long-context work and Llama 3 8B Instruct for tighter calls. If your workload also depends on provider fit, start with Llama 3 8B Instruct; if it depends on long-context analysis, run the same evaluation with Llama 3.1 405B.
Continue comparing
Last reviewed: 2026-05-11. Data sourced from public model cards and provider documentation.