Google Gemini 2.5
by Stephen M. Walker II, Co-Founder / CEO
Introduction
Google unveiled the Gemini 2.5 series during the I/O 2025 keynote. Building on the March release of 2.5 Pro, the update improves reasoning, multimodal comprehension, and developer tooling. These enhancements now power Search's AI Mode, the Gemini app, and enterprise services such as Vertex AI.
Key Performance Enhancements
- Deep Think — an experimental reasoning mode that evaluates multiple hypotheses before answering. It notably boosts math and coding performance.
- Native audio output delivers expressive, emotion-aware speech for more natural conversations.
- Enhanced security mitigates prompt injection attacks when using tools.
- Agent Mode via Project Mariner enables autonomous web browsing and transactions.
Together, these changes make Gemini interactions more reliable and capable.
Model Variants
Gemini 2.5 ships in two main variants:
- 2.5 Pro — optimized for advanced coding and reasoning with Deep Think and a 1 million token context window.
- 2.5 Flash — tuned for speed and lower cost, using 20–30 % fewer tokens while improving reasoning scores.
2.5 Pro Model Card
| Attribute | Details |
|---|---|
| Developer | Google DeepMind |
| Release Date | May 20, 2025 |
| Access | Public preview on Vertex AI and Google AI Studio; general availability shortly after June 2025 |
| Context Window | 1 000 000 tokens with 2 000 000 planned in a later update |
| Input Modalities | Text, code, images, audio, and video |
| Key Features | Experimental Deep Think mode, native emotion-aware audio, multilingual support, enhanced security against indirect prompt injections |
| Benchmarks | Leading results on LiveCodeBench, USAMO, and MMMU |
| Pricing | $2.50 per 1 000 000 input tokens; $15.00 per 1 000 000 output tokens |
| Limitations | Deep Think limited to trusted testers; occasional hallucinations |
2.5 Flash Model Card
| Attribute | Details |
|---|---|
| Developer | Google DeepMind |
| Release Date | May 20, 2025 |
| Access | Preview in Google AI Studio, Vertex AI, and the Gemini app; general availability early June 2025 |
| Context Window | Inherits Gemini's long-context architecture (token limit undisclosed) |
| Input Modalities | Text, images, code, audio, and video |
| Key Features | Optimized for low latency and cost, using 20–30 % fewer tokens; configurable thinking budget per request |
| Benchmarks | Competitive reasoning, multimodal understanding, and code generation with sub-200 ms responses |
| Pricing | Consumption-based pricing with lower cost per token than Pro |
| Limitations | Slightly lower accuracy than Pro on complex tasks |
Benchmarks and Learning Focus
Gemini 2.5 Pro leads major leaderboards like WebDev Arena and LMArena, demonstrating strong coding and reasoning. Deep Think sets records on the USAMO exam, LiveCodeBench, and MMMU. Using the LearnLM approach, the model excels on pedagogical benchmarks, outperforming peers across five learning science principles.
Developer and Enterprise Experience
Gemini API and Vertex AI SDK now provide thought summaries showing each model's reasoning and tool usage. Enterprises can audit easier and set Thinking Budgets up to 32K tokens. MCP tools offer extensibility, and early testers on Vertex AI can evaluate Deep Think in a secure environment.
Access Plans
The AI Premium tier has been renamed Google AI Pro, adding Flow (Veo 2) and early Chrome integration. The Gemini AI Ultra subscription grants VIP access to Deep Think, Veo 3 video generation, Project Mariner, and more.
Gemini AI Ultra Subscription Card
| Attribute | Details |
|---|---|
| Plan Name | Gemini AI Ultra |
| Launch Date | May 20, 2025 |
| Price | US$249.99 per month with a 50 % introductory discount in the U.S. |
| Access | VIP access to Gemini 2.5 Pro Deep Think, Veo 3, Flow, NotebookLM, and Project Mariner |
| Storage | 30 TB across Google Photos, Drive, and Gmail |
| Extras | YouTube Premium subscription included |
| Limitations | Paid subscription required; initial roll-out limited to the U.S. |
Availability and Pricing
2.5 Flash is live in preview via the Gemini app, Google AI Studio, and Vertex AI. General availability arrives in early June with 2.5 Pro shortly after. Gemini AI Ultra launches in the US with a 50 % discount and will expand to 70+ countries. Students in select markets receive a free year of AI Pro.
Implications and Next Steps
With Gemini 2.5 integrated into Search's AI Mode, Chrome, and Google Workspace, users gain more proactive assistance. Upcoming features include deep search, AI-generated charts, and agentic checkout. Enterprises are testing extraction agents in Box and workflows in Geotab, aiming for over 90 % document accuracy. Google plans wider Deep Think access after further safety evaluations.