Llama 3 8B Instruct vs Phi-3 Mini 4k
Llama 3 8B Instruct (2024) and Phi-3 Mini 4k (2024) are compact production models from AI at Meta and Microsoft Research. Llama 3 8B Instruct ships a 8K-token context window, while Phi-3 Mini 4k ships a 4K-token context window. On MMLU PRO, Phi-3 Mini 4k leads by 5.2 pts. On pricing, Llama 3 8B Instruct costs $0.03/1M input tokens versus $0.05/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
Llama 3 8B Instruct is ~67% cheaper at $0.03/1M; pay for Phi-3 Mini 4k only for provider fit.
Specs
| Released | 2024-04-18 | 2024-04-23 |
| Context window | 8K | 4K |
| Parameters | 8B | 3.8B |
| Architecture | decoder only | decoder only |
| License | Open Source | Open Source |
| Knowledge cutoff | - | - |
Pricing and availability
| Llama 3 8B Instruct | Phi-3 Mini 4k | |
|---|---|---|
| Input price | $0.03/1M tokens | $0.05/1M tokens |
| Output price | $0.04/1M tokens | $0.25/1M tokens |
| Providers |
Capabilities
| Llama 3 8B Instruct | Phi-3 Mini 4k | |
|---|---|---|
| Vision | ||
| Multimodal | ||
| Reasoning | ||
| Function calling | ||
| Tool use | ||
| Structured outputs | ||
| Code execution |
Benchmarks
| Benchmark | Llama 3 8B Instruct | Phi-3 Mini 4k |
|---|---|---|
| MMLU PRO | 40.5 | 45.7 |
| Google-Proof Q&A | 44.8 | 40.9 |
| HumanEval | 68.2 | 59.8 |
| Instruction-Following Evaluation | 59.5 | 45.0 |
| Massive Multitask Language Understanding | 76.9 | 68.2 |
| HellaSwag | 91.1 | 87.1 |
Deep dive
On shared benchmark coverage, MMLU PRO has Llama 3 8B Instruct at 40.5 and Phi-3 Mini 4k at 45.7, with Phi-3 Mini 4k ahead by 5.2 points; Google-Proof Q&A has Llama 3 8B Instruct at 44.8 and Phi-3 Mini 4k at 40.9, with Llama 3 8B Instruct ahead by 3.9 points; HumanEval has Llama 3 8B Instruct at 68.2 and Phi-3 Mini 4k at 59.8, with Llama 3 8B Instruct ahead by 8.4 points. The largest visible gap is 8.4 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.
For cost, Llama 3 8B Instruct lists $0.03/1M input and $0.04/1M output tokens, while Phi-3 Mini 4k lists $0.05/1M input and $0.25/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Llama 3 8B Instruct lower by about $0.08 per million blended tokens. Availability is 17 providers versus 4, so concentration risk also matters.
Choose Llama 3 8B Instruct when long-context analysis, larger context windows, and lower input-token cost are central to the workload. Choose Phi-3 Mini 4k when provider fit 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 Phi-3 Mini 4k?
Llama 3 8B Instruct supports 8K tokens, while Phi-3 Mini 4k supports 4K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Llama 3 8B Instruct or Phi-3 Mini 4k?
Llama 3 8B Instruct is cheaper on tracked token pricing. Llama 3 8B Instruct costs $0.03/1M input and $0.04/1M output tokens. Phi-3 Mini 4k costs $0.05/1M input and $0.25/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Llama 3 8B Instruct or Phi-3 Mini 4k open source?
Llama 3 8B Instruct is listed under Open Source. Phi-3 Mini 4k 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 Phi-3 Mini 4k?
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 Phi-3 Mini 4k?
Llama 3 8B Instruct is available on AWS Bedrock, DeepInfra, OctoAI API, Fireworks AI, and Alibaba Cloud PAI-EAS. Phi-3 Mini 4k is available on Microsoft Foundry, NVIDIA NIM, Baseten API, and Replicate API. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
When should I pick Llama 3 8B Instruct over Phi-3 Mini 4k?
Llama 3 8B Instruct is ~67% cheaper at $0.03/1M; pay for Phi-3 Mini 4k only for provider fit. If your workload also depends on long-context analysis, start with Llama 3 8B Instruct; if it depends on provider fit, run the same evaluation with Phi-3 Mini 4k.
Continue comparing
Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.