# Gemini 3.1 Pro Preview vs Gemini 3.5 Flash

As of Oct 15, 2026, Gemini 3.1 Pro Preview leads Gemini 3.5 Flash in 6 of 8 shared categories: General LLM, Reasoning, Science, Long context, Vision, and Abstraction (ARC).

Gemini 3.1 Pro Preview: $4.5 per 1M blended tokens.

Gemini 3.5 Flash: $3.375 per 1M blended tokens.

Gemini 3.1 Pro Preview: closed weights.

Gemini 3.5 Flash: closed weights.

- Which to pick, General LLM: As of Oct 15, 2026, Gemini 3.1 Pro Preview leads Gemini 3.5 Flash in General LLM at #15 against #25.
- Which to pick, Reasoning: As of Oct 15, 2026, Gemini 3.1 Pro Preview leads Gemini 3.5 Flash in Reasoning at #14 against #35.
- Which to pick, Science: As of Oct 15, 2026, Gemini 3.1 Pro Preview leads Gemini 3.5 Flash in Science at #7 against #18.
- Which to pick, Coding › Web dev: As of Oct 15, 2026, Gemini 3.5 Flash leads Gemini 3.1 Pro Preview in Coding › Web dev at #52 against #63.
- Which to pick, Long context: As of Oct 15, 2026, Gemini 3.1 Pro Preview leads Gemini 3.5 Flash in Long context at #12 against #33.
- Which to pick, Vision: As of Oct 15, 2026, Gemini 3.1 Pro Preview leads Gemini 3.5 Flash in Vision at #25 against #29.
- Which to pick, Factuality: As of Oct 15, 2026, Gemini 3.5 Flash leads Gemini 3.1 Pro Preview in Factuality at #14 against #21.
- Which to pick, Abstraction (ARC): As of Oct 15, 2026, Gemini 3.1 Pro Preview leads Gemini 3.5 Flash in Abstraction (ARC) at #2 against #12.

As of Oct 15, 2026, Gemini 3.1 Pro Preview is state of the art on best per dollar in Math (since Oct 14, 2026; sources Humanity's Last Exam; methodology v1.0).

As of Oct 15, 2026, Gemini 3.5 Flash is ranked #12 in Abstraction (ARC) (since Oct 15, 2026; sources ARC-AGI; methodology v1.0).