Llama 3 8BvsLlama 3.1 405B
Meta AI vs Meta AI — Side-by-side model comparison
Head-to-Head Comparison
| Metric | Llama 3 8B | Llama 3.1 405B |
|---|---|---|
| Provider | ||
| Arena Rank | — | #9 |
| Context Window | 8K | 128K |
| Input Pricing | Free (open)/1M tokens | Free (open)/1M tokens |
| Output Pricing | Free (open)/1M tokens | Free (open)/1M tokens |
| Parameters | 8B | 405B |
| Open Source | Yes | Yes |
| Best For | Edge deployment, fast inference, fine-tuning | Complex reasoning, coding, multilingual tasks |
| Release Date | Apr 18, 2024 | Jul 23, 2024 |
Llama 3 8B
Llama 3 8B is Meta's compact model that delivered breakthrough performance for its size class, outperforming the much larger Llama 2 70B on many benchmarks despite being nearly 10x smaller. Its efficiency and strong instruction following made it the most popular starting point for fine-tuning custom models in the open-source community.
View Meta AI profile →Llama 3.1 405B
Llama 3.1 405B is Meta's largest and most capable open-source language model, representing a major milestone as the first open model to rival top proprietary systems like GPT-4 and Claude 3.5 Sonnet across many benchmarks. With 405 billion parameters and a 128K context window, it excels at complex reasoning, coding, multilingual translation, and tool use. Its open-weight nature has made it a foundation for the open-source AI ecosystem, enabling organizations to deploy frontier-level AI without vendor lock-in.
View Meta AI profile →Key Differences: Llama 3 8B vs Llama 3.1 405B
Llama 3.1 405B supports a larger context window (128K), allowing it to process longer documents in a single request.
Llama 3 8B has 8B parameters vs Llama 3.1 405B's 405B, which affects inference speed and capability.
When to use Llama 3 8B
- +Your use case involves edge deployment, fast inference, fine-tuning
When to use Llama 3.1 405B
- +You need to process long documents (128K context)
- +Your use case involves complex reasoning, coding, multilingual tasks
The Verdict
Llama 3.1 405B wins our head-to-head comparison with 3 out of 5 category wins. It's the stronger choice for complex reasoning, coding, multilingual tasks, though Llama 3 8B holds an edge in edge deployment, fast inference, fine-tuning.
Last compared: March 2026 · Data sourced from public benchmarks and official pricing pages