Llama 3.1 405B vs o3-pro
Compare Meta (via Together AI) and OpenAI AI models
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
Llama 3.1 405B
o3-pro
Cost Differences
o3-pro costs more than Llama 3.1 405B
Feature Comparison
| Feature | Llama 3.1 405B | o3-pro |
|---|---|---|
| Provider | Meta (via Together AI) | OpenAI |
| Input Price | $3.50/1M tokens | $20.00/1M tokens |
| Output Price | $3.50/1M tokens | $80.00/1M tokens |
| Context Window | 128,000 tokens | 1,000,000 tokens |
| Max Output | 32,768 tokens | 131,072 tokens |
| Category | flagship | reasoning |
| Capabilities | textcodereasoning | textreasoningcode |
| Release Date | 7/23/2024 | 6/10/2025 |
Llama 3.1 405B vs o3-pro: Which Should You Choose?
Choosing between Llama 3.1 405B and o3-pro depends on your priorities: cost efficiency, context length, or raw capability. Llama 3.1 405B is the more affordable option at $3.50/1M input tokens — 83% cheaper than o3-pro. Meanwhile, o3-pro offers a significantly larger context window at 1,000,000 tokens vs 128,000 for Llama 3.1 405B.
These models come from different providers — Meta (via Together AI) and OpenAI — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with Meta (via Together AI), switching to OpenAIinvolves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
These models target different tiers: Llama 3.1 405B is a flagship model while o3-pro is reasoning. This means they're optimized for different workloads. Llama 3.1 405B is built for complex tasks that require deeper reasoning, while o3-pro offers better value for routine operations.
Output costs matter too. Llama 3.1 405B charges $3.50/1M output tokens vs $80.00 for o3-pro. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Llama 3.1 405B has the edge here at $3.50/1M output tokens.
Best Use Cases
Choose Llama 3.1 405B when:
- • Budget is a primary concern
- • You're already using Meta (via Together AI)'s API ecosystem
Choose o3-pro when:
- • You need a larger context window (1,000,000 tokens)
- • You need longer outputs (up to 131,072 tokens)
- • You're already using OpenAI's API ecosystem
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
Llama 3.1 405B (Meta (via Together AI))
o3-pro (OpenAI)
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