Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning) vs Grok 4.1 Fast (Reasoning)
Comparing 2 AI models · 5 benchmarks · Google, xAI
Composite Indices
Intelligence, Coding, Math
Standard Benchmarks
Academic and industry benchmarks
Benchmark Winners
Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning)
No clear wins
Grok 4.1 Fast (Reasoning)
- GPQA
- MMLU Pro
- HLE
- LiveCodeBench
- AIME 2025
| Metric | Go Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning) | xA Grok 4.1 Fast (Reasoning) |
|---|---|---|
| Pricing Per 1M tokens | ||
| Input Cost | $0.30/1M | $0.20/1M |
| Output Cost | $2.50/1M | $0.50/1M |
| Blended Cost 3:1 input/output ratio | $0.85/1M | $0.28/1M |
| Specifications | ||
| Organization Model creator | xAI | |
| Release Date Launch date | Sep 25, 2025 | Nov 19, 2025 |
| Performance & Speed | ||
| Throughput Output speed | 237.7 tok/s | 69.0 tok/s |
| Time to First Token (TTFT) Initial response delay | 345ms | 16962ms |
| Latency Time to first answer token | 345ms | 16962ms |
| Composite Indices | ||
| Intelligence Index Overall reasoning capability | 46.7 | 64.1 |
| Coding Index Programming ability | 37.8 | 49.7 |
| Math Index Mathematical reasoning | 56.7 | 89.3 |
| Standard Benchmarks | ||
| GPQA Graduate-level reasoning | 76.6% | 85.3% |
| MMLU Pro Advanced knowledge | 83.6% | 85.4% |
| HLE Hard language evaluation | 7.8% | 17.6% |
| LiveCodeBench Real-world coding tasks | 62.5% | 82.2% |
| MATH 500 Mathematical problems | — | — |
| AIME 2025 Advanced math competition | 56.7% | 89.3% |
| AIME (Original) Math olympiad problems | — | — |
| SciCode Scientific code generation | 37.5% | 44.2% |
| LCR Code review capability | 56.7% | 68.0% |
| IFBench Instruction-following | 43.5% | 52.7% |
| TAU-bench v2 Tool use & agentic tasks | 28.4% | 93.3% |
| TerminalBench Hard CLI command generation | 13.5% | 22.7% |
Key Takeaways
Grok 4.1 Fast (Reasoning) offers the best value at $0.20/1M, making it ideal for high-volume applications and cost-conscious projects.
Grok 4.1 Fast (Reasoning) leads in reasoning capabilities with a 85.3% GPQA score, excelling at complex analytical tasks and problem-solving.
Grok 4.1 Fast (Reasoning) achieves a 49.7 coding index, making it the top choice for software development and code generation tasks.
All models support context windows of ∞+ tokens, suitable for processing lengthy documents and maintaining extended conversations.
When to Choose Each Model
Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning)
- General-purpose AI
- Versatile applications
Grok 4.1 Fast (Reasoning)
- Cost-sensitive applications
- High-volume processing
- Complex reasoning tasks
- Research & analysis
- Code generation
- Software development
Try Models for Free
Try Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning) for FREE
No credit card or account required.
Try Grok 4.1 Fast (Reasoning) for FREE
No credit card or account required.
Cost Calculator
Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning) Grok 4.1 Fast (Reasoning) Costs are estimates based on API pricing. Actual costs may vary based on caching, batch processing, and volume discounts.
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