Is Gemini 3.1 Pro better than Grok 4 for reasoning?

I can’t safely say that Gemini 3.1 Pro is better than Grok 4 for reasoning in general.

“Reasoning” depends heavily on the task: math, coding, scientific Q&A, long-document analysis, agentic tool use, legal-style synthesis, and everyday problem solving can produce different winners. Model rankings also change quickly, and public benchmark results may not match your real prompts.

The best way to compare them is a small side-by-side test:

1. Use 20–50 real prompts from your workflow.
2. Run both models with the same instructions and comparable settings.
3. Score final-answer correctness, reasoning reliability, hallucinations, ability to follow constraints, and consistency across repeated runs.
4. Include any features that matter to you, such as context length, tool access, file handling, latency, and cost.
5. Check recent independent benchmarks, but treat them as supporting evidence rather than a final answer.

Bottom line: Gemini 3.1 Pro might be better for some reasoning workloads and Grok 4 might be better for others, but I would not claim a general winner without current benchmark evidence and task-specific testing.