Gemini 3.1 Pro Preview: The new leader in AI

Google is once again the leader in AI: Gemini 3.1 Pro Preview leads the Artificial Analysis Intelligence Index, 4 points ahead of Claude Opus 4.6 while costing less than half as much to run

GoogleDeepMind gave us pre-release access to Gemini 3.1 Pro Preview. It leads 6 of the 10 evaluations that make up the Artificial Analysis Intelligence Index and improves significantly over Gemini 3 Pro Preview across capabilities, with the biggest gains in reasoning and knowledge, coding, and hallucination reduction.

Gemini 3.1 Pro Preview also remains relatively token efficient, using ~57M tokens to run the Artificial Analysis Intelligence Index (+1M from Gemini 3 Pro Preview), lower than other frontier models at max reasoning settings such as Opus 4.6 (max) and GPT-5.2 (xhigh). Combined with lower per-token pricing, Gemini 3.1 Pro Preview is cost-efficient among frontier peers, costing less than half as much as Opus 4.6 (max) to run the full Intelligence Index, though still nearly 2x the leading open-weights model, GLM-5.

Key Takeaways:

➤ State-of-the-art intelligence at lower costs: Gemini 3.1 Pro Preview is leading 6 of the 10 evaluations that make up the Artificial Analysis Intelligence Index at less than half the cost to run of frontier peers from @OpenAI and @AnthropicAI. It obtains the highest score in Terminal-Bench Hard (agentic coding), AA-Omniscience (knowledge & hallucination), Humanity’s Last Exam (reasoning & knowledge), GPQA-Diamond (scientific reasoning), SciCode (coding) and CritPt (research-level physics). The CritPt score is particularly notable, scoring 18% on unpublished, research-level physics reasoning problems, over 5 p.p. above the next best model

➤ Improved real-world agentic performance, but not leading: Gemini 3.1 Pro Preview shows an improvement in GDPval-AA, our agentic evaluation focusing on real-world tasks, but is still not the leading model in this area. The model increases its ELO score over 100 points to 1316 (up from Gemini 3 Pro Preview), however still sits behind Claude Sonnet 4.6, Opus 4.6, GPT-5.2 (xhigh), and GLM-5

➤ Leading coding abilities: Gemini 3.1 Pro Preview leads the Artificial Analysis Coding Index, achieving the highest score in both Terminal-Bench Hard (54%) and SciCode (59%)

➤ Reduced hallucinations: Gemini 3.1 Pro Preview shows a major improvement in tendency to guess incorrectly when it doesn’t know the answer, reducing its AA-Omniscience hallucination rate by 38 p.p. from Gemini 3 Pro Preview

➤ Maintained token and cost efficiency: Gemini 3.1 Pro Preview improves without material increases in cost or token usage. It uses only ~2% more tokens to run the Artificial Analysis Intelligence Index than Gemini 3 Pro Preview, and keeps the same pricing ($2/$12 per 1M input/output tokens for ≤200k context). Its cost to run the Artificial Analysis Intelligence Index of $892 is less than half of frontier models such as Opus 4.6 (max) and GPT-5.2 (xhigh), though still ~2x the cost of leading open weights models such as GLM 5 ($547)

➤ Google takes top 3 spots in multi-modality: Gemini 3.1 Pro Preview ranks #1 on MMMU-Pro, our multimodal understanding and reasoning benchmark, ahead of Gemini 3 Pro Preview and Gemini 3 Flash, reinforcing Google’s leadership in multimodal reasoning

➤ Other model details: Gemini 3.1 Pro Preview retains the same 1 million token context window as its predecessor, and includes support for tool calling, structured outputs, and JSON mode

Artificial Analysis Intelligence Index (18 Feb '26)

Gemini 3.1 Pro Preview improves without becoming more expensive or much more verbose, using only ~1M more tokens compared to Gemini 3 Pro Preview, representing a $72 increase in cost to run the Artificial Analysis Intelligence Index. This cost is less than half of frontier peers such as Opus 4.6 (max) and GPT-5.2 (xhigh), though still ~2x the cost of leading open-weights models such as GLM 5 and Kimi K2.5.

Output Tokens Used to Run Artificial Analysis Intelligence Index (18 Feb '26)

Gemini 3.1 Pro Preview has an average speed of 114 output tokens/s. Although slightly slower than its predecessor (-10 t/s), it remains one of the fastest models in the top 10 of the Artificial Analysis Intelligence Index, trailing only other Google models (Gemini 3 Flash and Gemini 3 Pro Preview).

Output Speed (18 Feb '26)

The 6 evaluations that Gemini 3.1 Pro Preview leads in the Artificial Analysis Intelligence Index include CritPt and Terminal-Bench Hard. CritPt tests models on unpublished, research-level physics reasoning problems. In CritPt, Gemini 3.1 Pro Preview improves by ~9 p.p. and now leads the next-best model by 5 points. It also leads Terminal-Bench Hard, an agentic terminal-use benchmark, slightly ahead of Claude Sonnet 4.6.

CritPt Benchmark Leaderboard - Results (18 Feb '26)

Gemini 3.1 Pro Preview also leads our knowledge and hallucination benchmark, AA-Omniscience. The model improves by 17 points on our key metric, the Omniscience Index, which rewards models for knowing the answer and penalizes incorrect guesses.

This increase is driven by a reduction in the model’s tendency to guess incorrectly when it doesn’t know the answer, reducing its AA-Omniscience hallucination rate from 88% to 50%. Gemini 3.1 Pro Preview also achieves AA-Omniscience accuracy of 53% (comparable to Gemini 3 Pro Preview), reflecting strong embedded knowledge.

AA-Omniscience Index (18 Feb '26)

Gemini 3.1 Pro Preview ranks #1 on MMMU-Pro, our multimodal understanding and reasoning benchmark, ahead of Gemini 3 Pro Preview and Gemini 3 Flash, reinforcing Google’s leadership in multimodal reasoning.

MMMU-Pro Benchmark Leaderboard - Results (18 Feb '26)

Full breakdown of results

Intelligence Evaluations (18 Feb '26)

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Further analysis on Artificial Analysis: https://artificialanalysis.ai/models/gemini-3-1-pro-preview