Grok 3 Mini vs GPT-5.1
Detailed pricing comparison and cost analysis.
Updated September 2026
Cost Simulator
| Feature | Grok 3 Mini | GPT-5.1 |
|---|---|---|
| Provider | xAI | OpenAI |
| Input Price (1M) | $0.30 | $1.25 |
| Output Price (1M) | $0.50 | $10.00 |
| Context Window | 131,000 | 400,000 |
Verdict
Grok 3 Mini costs $0.30 per 1M input tokens and $0.50 per 1M output tokens. GPT-5.1 costs $1.25 per 1M input tokens and $10.00 per 1M output tokens. Grok 3 Mini is 76% cheaper on input tokens than GPT-5.1. For output tokens, Grok 3 Mini is the more affordable option at $0.50/1M vs $10.00.
On context window, GPT-5.1 supports 400,000 tokens — meaning it can fit more conversation history, documents, or code in a single request. This matters for RAG pipelines, long document analysis, and agentic workflows where context builds up over many turns.
When to choose Grok 3 Mini
- ✓ You need the lowest input token cost ($ 0.30/1M)
- ✓ Your workload is output-heavy — Grok 3 Mini generates text cheaper
- ✓ You are already integrated with xAI
When to choose GPT-5.1
- ✓ You need a larger context window (400,000 tokens)
- ✓ You are already integrated with OpenAI
Use the calculator above to simulate your specific workload and find the exact break-even point. For most applications, the cheapest model is the one that minimises your total monthly bill given your input-to-output token ratio.
Frequently Asked Questions
Is Grok 3 Mini cheaper than GPT-5.1? ▼
Grok 3 Mini is cheaper on input tokens at $0.30/1M vs $1.25/1M for GPT-5.1 — a 76% saving.
What is the context window of Grok 3 Mini vs GPT-5.1? ▼
Grok 3 Mini has a 131,000-token context window. GPT-5.1 has a 400,000-token context window. GPT-5.1 supports the larger context, suitable for longer documents and agentic workflows.
Which model is better: Grok 3 Mini or GPT-5.1? ▼
The best choice depends on your use case. For cost efficiency on input tokens, Grok 3 Mini is the cheaper option. For maximum context length, GPT-5.1 supports 400,000 tokens. Use the comparison table above to find the right fit for your workload.