Grok 4.1 Fast vs Llama 3.1 8B
Grok 4.1 Fast vs Llama 3.1 8B: Llama 3.1 8B is cheaper for input-heavy usage ($0.18/M vs $0.20/M input tokens), while Grok 4.1 Fast is better for long-context tasks (2,000,000 tokens).
Direct answer: choose Llama 3.1 8B for lower token spend and choose Grok 4.1 Fast when your workload needs longer context.
Compare input and output token pricing, context windows, and monthly cost estimates on one page so you can pick the cheaper model fast.
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
Grok 4.1 Fast
Llama 3.1 8B
Cost Differences
Llama 3.1 8B costs less than Grok 4.1 Fast
Quick Recommendation
Winner for direct API pricing: Llama 3.1 8B. At the default workload, Llama 3.1 8B saves about $0.54/month ($6.57/year) versus Grok 4.1 Fast.
Feature Comparison
| Feature | Grok 4.1 Fast | Llama 3.1 8B |
|---|---|---|
| Provider | xAI | Meta (via Together AI) |
| Input Price | $0.20/1M tokens | $0.18/1M tokens |
| Output Price | $0.50/1M tokens | $0.18/1M tokens |
| Context Window | 2,000,000 tokens | 128,000 tokens |
| Max Output | 131,072 tokens | 32,768 tokens |
| Category | efficient | efficient |
| Capabilities | textreasoningcode | textcode |
| Release Date | 1/15/2026 | 7/23/2024 |
Grok 4.1 Fast vs Llama 3.1 8B: Which Should You Choose?
Choosing between Grok 4.1 Fast 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 — 10% cheaper than Grok 4.1 Fast. Meanwhile, Grok 4.1 Fast offers a significantly larger context window at 2,000,000 tokens vs 128,000 for Llama 3.1 8B.
These models come from different providers — xAI and Meta (via Together AI) — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with xAI, switching to Meta (via Together AI)involves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
Both models are in the efficient category, making this a direct head-to-head comparison. At scale — say 10,000 requests per day — the cost difference adds up: Llama 3.1 8B would save you roughly $54.00/month compared to Grok 4.1 Fast. For startups and indie developers, that difference can be significant.
Output costs matter too. Grok 4.1 Fast charges $0.50/1M 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.
Best Use Cases
Choose Grok 4.1 Fast when:
- • You need a larger context window (2,000,000 tokens)
- • You need more capabilities (reasoning)
- • You need longer outputs (up to 131,072 tokens)
- • You're already using xAI's API ecosystem
- • You're running high-volume, latency-sensitive workloads
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
Pros and Caveats at a Glance
Grok 4.1 Fast
- • Input pricing: $0.20/M tokens
- • Output pricing: $0.50/M tokens
- • Context window: 2,000,000 tokens
- • Max output: 131,072 tokens
Watch out for
- • Higher input cost than Llama 3.1 8B
- • Higher output cost than Llama 3.1 8B
Llama 3.1 8B
- • Input pricing: $0.18/M tokens
- • Output pricing: $0.18/M tokens
- • Context window: 128,000 tokens
- • Max output: 32,768 tokens
Watch out for
- • Smaller context window than Grok 4.1 Fast
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
Grok 4.1 Fast (xAI)
Llama 3.1 8B (Meta (via Together AI))
Start using Grok 4.1 Fast today
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Sign Up for Meta (via Together AI) →Frequently Asked Questions
Which is cheaper, Grok 4.1 Fast or Llama 3.1 8B?▼
What is the context window difference between Grok 4.1 Fast and Llama 3.1 8B?▼
Which model is better for AI Chatbot?▼
Which model has better overall pricing for heavy usage?▼
Where can I compare xAI and Meta (via Together AI) API pricing beyond this model matchup?▼
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