Quick answer: Llama 4 Scout is Meta's April 2025 open-weight multimodal MoE model featuring a 10M-token context window — the largest of any open-weight model at launch. It scores 90.7% on AI2 Reasoning Challenge and 74.3% on MMLU-Pro with 17B active parameters. Available under the Llama 4 License with open weights on Hugging Face.
Where Llama 4 Scout leads
Where it lags
Best for: Open-weight deployments requiring extremely long context (book-length documents, whole-repository analysis); tasks where the 10M context window is the primary requirement.
Llama 4 Scout is Meta's efficient model in the Llama 4 family, prioritising maximum context length over peak accuracy. Its 10M-token context window is 10× that of Llama 4 Maverick and GPT-4.1 — making it uniquely suited for tasks that require processing an entire codebase, book, or document collection in a single pass.
Like Maverick, Scout uses a Mixture of Experts (MoE) architecture with 17B active parameters, making inference efficient. However, Scout is designed with fewer experts (16 per token vs Maverick's 128) — enabling the extreme context extension at the cost of reduced peak accuracy.
At 90.7% AI2 Reasoning Challenge and 74.3% MMLU-Pro, Scout is a capable model across academic knowledge tasks, but Maverick outperforms it on standard benchmarks. For tasks that don't specifically require the 10M context window, Llama 4 Maverick is the recommended choice within the Llama 4 family.
| Field | Value |
|---|---|
| Organization | Meta |
| Active parameters | 17B (MoE, 16 experts) |
| Context window | 10,000,000 tokens |
| License | Llama 4 License |
| HuggingFace | meta-llama/Llama-4-Scout-17B-16E-Instruct |
| Release date | April 5, 2025 |
| Knowledge cutoff | January 2025 |
| Modality | Text + Vision (multimodal) |
| Architecture | MoE (Mixture of Experts) |
Llama 4 Scout is available as open weights — free to download and self-host. Hosted API access is available via Meta AI and third-party providers (Together AI, Groq, etc.) at market rates.
Llama 4 Scout has a 10,000,000-token context window — roughly 7,500 pages of text, or a large codebase in a single request. This is the largest context window of any open-weight model, and matches or exceeds all closed-source models except Gemini 1.5 Pro Extended.
| Benchmark | Score | Source | Date |
|---|---|---|---|
| AI2 Reasoning Challenge | 90.7% | Benchgen evaluation | 2025-07 |
| MMLU-Pro | 74.3% | Benchgen evaluation | 2025-07 |
| BigCodeBench | 16.9% | Benchgen evaluation | 2025-07 |
| Model | Context | AI2 RC | MMLU-Pro | Weights |
|---|---|---|---|---|
| Llama 4 Scout | 10M | 90.7% | 74.3% | Open |
| Llama 4 Maverick | 1M | 93.8% | 80.5% | Open |
| GPT-4.1 | 1M | 97.1% | — | Closed |
| Gemini 2.5 Pro | 1M | — | — | Closed |
Scout vs Maverick: 10× larger context window; lower accuracy on standard benchmarks. Choose Scout when the 10M context window is a hard requirement; choose Maverick for better performance on standard tasks.
# Via Together AI (hosted)
from together import Together
client = Together(api_key="YOUR_API_KEY")
response = client.chat.completions.create(
model="meta-llama/Llama-4-Scout-17B-16E-Instruct",
messages=[{"role": "user", "content": "Analyse this entire codebase..."}],
)
print(response.choices[0].message.content)Specs from Meta's official Llama 4 announcement (April 5, 2025) and Benchgen evaluations. Last updated 2026-07-24.
This model isn’t on any benchmark leaderboard yet.