Gemini 3.1 vs Gemini 2.5: Google's AI Upgrade Compared

Quick Verdict

Gemini 3.1 Pro is a big upgrade. It leads 13 out of 16 benchmarks, scores 94.3% on GPQA Diamond (up from Gemini 2.5's ~70s range), and outputs at 120.4 tokens per second. The three-tier thinking system, animated SVG generation, and improved coding make it worth switching. It's one of the best AI models available right now.

Comparison Table

Feature	Gemini 2.5 Pro	Gemini 3.1 Pro
Context window	1M	1M
GPQA Diamond	~72%	94.3%
ARC-AGI-2	~30%	77.1%
SWE-bench Verified	~63%	80.6%
Output speed	~50 t/s	120.4 t/s
Thinking	Basic	Three-tier system
SVG generation	Static	Animated
Benchmarks led	~5/16	13/16
API (input/output)	$1.25/$10	$2/$12
Subscription	$19.99/mo	$19.99/mo
Intelligence Index	~45	57

Benchmark Improvements

The numbers tell the story. GPQA Diamond went from ~72% to 94.3%. ARC-AGI-2 from ~30% to 77.1%. SWE-bench Verified from ~63% to 80.6%. These aren't incremental improvements. Gemini 3.1 Pro is a generational leap. It now leads 13 out of 16 standard AI benchmarks, tied with GPT-5.4 on the Intelligence Index at 57.

Speed

Output speed more than doubled, from ~50 tokens per second to 120.4. This is the fastest frontier model available. In practice, responses feel nearly instant for most queries. For API users processing thousands of calls, this speed improvement directly reduces latency and improves user experience.

Three-Tier Thinking

Gemini 2.5 had basic thinking capabilities. Gemini 3.1 Pro has a three-tier system that automatically adjusts reasoning depth based on problem complexity. Simple factual questions get fast answers. Complex multi-step problems get deeper analysis. This is similar to Claude's adaptive thinking but implemented differently. In practice, it means better answers without manually tuning settings.

Animated SVGs

This is a unique feature. Gemini 3.1 Pro can generate animated SVG graphics, useful for diagrams, flowcharts, and visual explanations. I tested it by asking for an animated flowchart of a CI/CD pipeline. It produced a clean, animated diagram that I could embed directly in a webpage. No other frontier model does this.

Coding

SWE-bench Verified at 80.6% puts Gemini 3.1 Pro in the same tier as Claude Opus 4.6 (80.8%) for coding. Combined with its faster output speed, Gemini is now a serious option for developers. It's especially good for tasks where quick iteration matters more than absolute code perfection.

Pricing

API pricing went up slightly ($2/$12 vs $1.25/$10 for 2.5), but the performance improvements more than justify the increase. The consumer subscription stayed at $19.99/month. Google also launched an Ultra plan at $249.99/month for heavy users. For broader access, Admix includes Gemini plus Claude, GPT-5.4, and 350+ AI models from $10/month (or $8/month billed annually).

Should You Upgrade?

Absolutely. If you're on Google AI Pro, you already have Gemini 3.1 Pro. If you're on the API, switch from 2.5 to 3.1. The performance improvement across every benchmark makes 2.5 obsolete for most use cases.

FAQ

Is Gemini 3.1 Pro the best AI model?

It leads the most benchmarks (13/16) and has the best GPQA Diamond score (94.3%). But Claude Opus 4.6 is slightly better at coding, and GPT-5.4 has better computer use. It's one of the top three models alongside GPT-5.4 and Claude.

Is the API price increase worth it?

Yes. Going from $1.25/$10 to $2/$12 is a modest increase for dramatically better performance. It's still cheaper than GPT-5.4 ($2.50/$15) and much cheaper than Claude Opus ($5/$25).