GPT-5.1 vs Llama 3.1 8B
Compare OpenAI and Meta (via Together AI) AI models
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
GPT-5.1
Llama 3.1 8B
Cost Differences
Llama 3.1 8B costs less than GPT-5.1
Feature Comparison
| Feature | GPT-5.1 | Llama 3.1 8B |
|---|---|---|
| Provider | OpenAI | Meta (via Together AI) |
| Input Price | $1.25/1M tokens | $0.18/1M tokens |
| Output Price | $10.00/1M tokens | $0.18/1M tokens |
| Context Window | 1,000,000 tokens | 128,000 tokens |
| Max Output | 131,072 tokens | 32,768 tokens |
| Category | flagship | efficient |
| Capabilities | textvisionaudiocodereasoning | textcode |
| Release Date | 11/12/2025 | 7/23/2024 |
GPT-5.1 vs Llama 3.1 8B: Which Should You Choose?
Choosing between GPT-5.1 and Llama 3.1 8B depends on your priorities: cost efficiency, context length, or raw capability. Llama 3.1 8B is the more affordable option at $0.18/1M input tokens — 86% cheaper than GPT-5.1. Meanwhile, GPT-5.1 offers a significantly larger context window at 1,000,000 tokens vs 128,000 for Llama 3.1 8B.
These models come from different providers — OpenAI and Meta (via Together AI) — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with OpenAI, switching to Meta (via Together AI)involves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
These models target different tiers: GPT-5.1 is a flagship model while Llama 3.1 8B is efficient. This means they're optimized for different workloads. GPT-5.1 is built for complex tasks that require deeper reasoning, while Llama 3.1 8B offers better value for routine operations.
Output costs matter too. GPT-5.1 charges $10.00/1M output tokens vs $0.18 for Llama 3.1 8B. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Llama 3.1 8B has the edge here at $0.18/1M output tokens.
Multimodal capabilities: GPT-5.1 supports vision (image inputs) while Llama 3.1 8B is text-only. If your application needs image understanding, this narrows your choice.
Best Use Cases
Choose GPT-5.1 when:
- • You need a larger context window (1,000,000 tokens)
- • You need more capabilities (vision, audio, reasoning)
- • You need longer outputs (up to 131,072 tokens)
- • You're already using OpenAI's API ecosystem
Choose Llama 3.1 8B when:
- • Budget is a primary concern
- • You're already using Meta (via Together AI)'s API ecosystem
- • You're running high-volume, latency-sensitive workloads
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
GPT-5.1 (OpenAI)
Llama 3.1 8B (Meta (via Together AI))
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