Llama 3.1 405BvsLlama 3.1 8B
Meta AI vs Meta AI — Side-by-side model comparison
Head-to-Head Comparison
| Metric | Llama 3.1 405B | Llama 3.1 8B |
|---|---|---|
| Provider | ||
| Arena Rank | #9 | #22 |
| Context Window | 128K | 128K |
| Input Pricing | Free (open)/1M tokens | Free (open)/1M tokens |
| Output Pricing | Free (open)/1M tokens | Free (open)/1M tokens |
| Parameters | 405B | 8B |
| Open Source | Yes | Yes |
| Best For | Complex reasoning, coding, multilingual tasks | Edge deployment, mobile, fast inference |
| Release Date | Jul 23, 2024 | Jul 23, 2024 |
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 →Llama 3.1 8B
Llama 3.1 8B is Meta's smallest model in the Llama 3.1 family, designed for environments where computational resources are limited but strong language understanding is still needed. Despite its compact 8 billion parameter size, it maintains a 128K context window and delivers impressive performance on coding, reasoning, and conversational tasks relative to its size. It runs efficiently on a single GPU and is widely used for edge deployment, mobile applications, and cost-sensitive production workloads.
View Meta AI profile →Key Differences: Llama 3.1 405B vs Llama 3.1 8B
Llama 3.1 405B ranks higher in arena benchmarks (#9) indicating stronger overall performance.
Llama 3.1 405B has 405B parameters vs Llama 3.1 8B's 8B, which affects inference speed and capability.
When to use Llama 3.1 405B
- +You need the highest quality output based on arena rankings
- +Your use case involves complex reasoning, coding, multilingual tasks
When to use Llama 3.1 8B
- +Your use case involves edge deployment, mobile, fast inference
The Verdict
Llama 3.1 405B wins our head-to-head comparison with 2 out of 5 category wins. It's the stronger choice for complex reasoning, coding, multilingual tasks, though Llama 3.1 8B holds an edge in edge deployment, mobile, fast inference.
Last compared: March 2026 · Data sourced from public benchmarks and official pricing pages