On November 18, Google released Gemini 3, and the headlines aren't exaggerated. If GPT-5.1 is the "Fast Brain" and Claude 4.5 is the "Diligent Worker," Gemini 3 is the "Deep Thinker."

For the first time in this AI cycle, Google isn't just catching up; they are setting the pace on the hardest metric of all: Reasoning.

The Headliner: "Deep Think" Mode

The killer feature of this release is Gemini 3 Deep Think.

While OpenAI’s "Thinking" mode is impressive, Google’s implementation feels like a generational leap in scientific and logical deduction.

• The Numbers: On "Humanity's Last Exam"—the new benchmark designed to break LLMs—Gemini 3 Deep Think scored 41.0%. For context, GPT-5.1 scored 31.6%. That is an 11% gap in pure, unassisted reasoning.
• How it feels: When you ask it a complex physics problem or a multi-layered riddle, it doesn't just chain thoughts together; it simulates multiple potential paths before answering. It feels less like a text predictor and more like a research partner.

For Developers: Welcome to "Antigravity"

If you are a coder, the most exciting part of this release isn't the model—it's the playground. Google launched Google Antigravity, a new agentic development platform (IDE) that finally delivers on the promise of "Vibe Coding."

What is "Vibe Coding"? It’s Google’s term for coding where you focus on the intent and design (the vibe), while the AI handles the implementation details.

• The Antigravity Difference: Unlike Cursor or VS Code Copilot which suggest lines of code, Antigravity allows you to drag-and-drop "agentic blocks." You can visually wire a "Database Agent" to a "Frontend Agent" and let Gemini 3 Pro manage the API glue between them.
• Tech Note: Gemini 3 Pro is currently topping the LiveCodeBench with an Elo of 2439, beating GPT-5.1 by nearly 200 points. It’s not just writing code; it’s architecting solutions.

The Ecosystem Play: Search & Multimodality

Google is flexing its ecosystem advantage hard. Gemini 3 isn't just a chatbot; it's now the engine behind AI Mode in Search.

• Dynamic UIs: If you ask for a "mortgage calculator," Gemini 3 doesn't just write code for one—it renders a fully interactive calculator widget directly in the chat interface.
• Native Multimodality: It processes video and audio with frightening speed. You can drop a 2-hour lecture video into the context window, and it will find a specific quote in seconds, thanks to the 1M token context window standard on Pro.

Benchmarks: The Three-Way Battle

Here is how the "Big Three" stack up right now:

The "Gotchas"

• The Confusion: Google’s naming scheme is still a mess. There is Gemini 3 Pro, Gemini 3 Deep Think (which is a mode, not a model?), and it’s all gated behind the "AI Ultra" subscription.
• Agentic Laziness: While it’s great at starting projects (Greenfield code), some users report that Antigravity struggles with refactoring messy, legacy codebases—an area where Claude 4.5 still reigns supreme.
• Safety Filters: The image generation and analysis guardrails are extremely aggressive. It often refuses to analyze medical images or "risky" visual content that GPT-5.1 handles fine.

Verdict: The New King of Logic

Stick with GPT-5.1 if you want the best general-purpose, conversational assistant that feels human.

Stick with Claude 4.5 if you are maintaining a massive legacy codebase and need a reliable employee to fix bugs.

Switch to Gemini 3 if you are a researcher, scientist, or architect. If your work involves solving novel problems that require deep, multi-step reasoning, or if you are building new apps from scratch, Gemini 3 is currently the smartest entity on the planet.