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[Reasoning]·PAP-DMZ04L·2025·March 18, 2026

Gemini 2.5 Pro Technical Report

2025

Google DeepMind

4 min readReasoningMultimodalScaling

Core Insight

Gemini 2.5 Pro pushes boundaries with unparalleled reasoning and multimodal capabilities, redefining AI benchmarks globally.

By the Numbers

63.8%

SWE-bench Verified coding score

86.7%

GPQA Diamond test score

91.7%

AIME 2025 test score

1 million tokens

context window support

#1

position on LMSys Chatbot Arena leaderboard

In Plain English

Gemini 2.5 Pro introduces a mode and multimodal input support to boost AI performance. It tops the LMSys Chatbot Arena and excels in coding with a 63.8% score on .

Knowledge Prerequisites

git blame for knowledge

To fully understand Gemini 2.5 Pro Technical Report, trace this dependency chain first. Papers in our library are linked — click to read them.

DIRECT PREREQIN LIBRARY
Scaling Laws for Neural Language Models

You must understand the principles governing how the performance of neural language models changes with the size of the model and dataset.

scaling lawsmodel performancedata efficiency
DIRECT PREREQIN LIBRARY
Chain-of-Thought Prompting Elicits Reasoning in Large Language Models

Understanding how chain-of-thought techniques improve the reasoning abilities of models is crucial for grasping the step-by-step reasoning mode in Gemini 2.5 Pro.

chain-of-thought reasoningprompt engineeringLLM reasoning enhancement
DIRECT PREREQIN LIBRARY
ReAct: Synergizing Reasoning and Acting in Language Models

This paper is necessary to learn how reasoning can be integrated with acting, which is a capability highlighted in thinking modes of advanced models.

reasoning and actingintegrated cognitive tasksadvanced model capabilities
DIRECT PREREQIN LIBRARY
Sparks of Artificial General Intelligence: Early Experiments with GPT-4

Understanding the capabilities and limitations of early large language models like GPT-4 gives context to the advancements seen in Gemini 2.5 Pro.

emergent abilitiesmodel limitationsconversational AI
DIRECT PREREQIN LIBRARY
Gemini 1.5: Unlocking multimodal understanding across millions of tokens of context

Gemini 1.5 lays the groundwork for Gemini 2.5 Pro's multimodal capabilities and large context windows.

multimodal inputscontext windowadvanced understanding

YOU ARE HERE

Gemini 2.5 Pro Technical Report

The Idea Graph

The Idea Graph
15 nodes · 15 edges
Click a node to explore · Drag to pan · Scroll to zoom
1,020 words · 6 min read13 sections · 15 concepts

Table of Contents

01

The World Before

101 words

Before Gemini 2.5 Pro, AI models were largely constrained by their inability to effectively handle complex tasks requiring extensive reasoning or the integration of multiple data formats. Models like GPT-3 and BERT, though powerful, struggled with maintaining context over long dialogues or documents, and they were limited to processing text inputs. This limitation meant that tasks requiring the fusion of text, images, audio, and video were often inadequately addressed. Despite these challenges, incremental improvements were made, such as expanding token limits and exploring multimodal capabilities, but these efforts were not sufficient to meet the rising demand for more versatile AI applications.

02

The Specific Failure

72 words

The main technical problem addressed by Gemini 2.5 Pro was the failure of previous models to adequately simulate human-like cognitive processing. This shortcoming was evident in tasks that required multi-step reasoning, such as complex problem-solving and planning, where models failed to break tasks into manageable sub-tasks. Additionally, the inability to handle multimodal inputs limited the applicability of these models in scenarios requiring comprehensive data interpretation, such as video analysis with textual context.

03

The Key Insight

81 words

The breakthrough insight for Gemini 2.5 Pro was the realization that AI could benefit from mimicking human cognitive processing. Imagine if AI could think like a human, breaking down complex tasks into smaller steps and rationalizing each decision. This insight led to the development of the 'Thinking Mode,' which allows the model to hierarchically parse and analyze information before generating responses. This approach enables the AI to better handle tasks requiring deep logical analysis and integrate information from various modalities effectively.

04

Architecture Overview

103 words

Gemini 2.5 Pro's architecture represents a significant leap forward in AI design. At its core is the introduction of the ',' which enables the model to process information hierarchically, akin to human cognitive processes. This mode is complemented by the ' Mode,' which breaks down complex tasks into manageable sub-tasks. Additionally, the model supports a ' Window,' allowing it to maintain context over much longer sequences. The architecture also includes ',' enabling the integration of text, images, audio, and video inputs. Together, these components create a versatile AI capable of handling a wide range of tasks.

05

Deep Dive: Thinking Mode

80 words

The '' is a novel feature of Gemini 2.5 Pro, inspired by human cognitive processes. This mode allows the model to hierarchically parse and analyze information before generating responses. By doing so, the AI can rationalize decisions in a manner similar to human thinking, improving its ability to handle complex tasks that require deep logical analysis. The mode's design was influenced by insights into human problem-solving techniques, where tasks are broken down into smaller steps for more efficient processing.

06

Deep Dive: Step-by-Step Reasoning Mode

74 words

The ' Mode' is a key component of Gemini 2.5 Pro that enhances its logical processing capabilities. This mode enables the model to break down complex tasks into smaller, manageable sub-tasks, similar to how humans approach problem-solving. By doing so, the model can process and analyze information more effectively, leading to improved performance on tasks requiring multi-step reasoning. This capability is crucial for applications like planning and problem-solving, where sequential logic is essential.

07

Deep Dive: Multimodal Input Support

80 words

Gemini 2.5 Pro's '' is a groundbreaking feature that allows the model to process and integrate various input types, including text, images, audio, and video. This capability enables the model to handle complex tasks that require understanding and combining information from different modalities. For example, the model can analyze a video while interpreting accompanying textual subtitles, providing a richer and more comprehensive understanding of the content. This feature expands the model's applicability across domains requiring multimodal data interpretation.

08

Training & Data

80 words

Training Gemini 2.5 Pro involved using a diverse set of data spanning text, images, audio, and video to ensure robust multimodal capabilities. The model was trained on a mixture of publicly available datasets and proprietary data, allowing it to learn from a wide range of content types. The training process employed advanced techniques like reinforcement learning from human feedback (RLHF) to fine-tune the model's responses and improve its decision-making capabilities. These strategies were crucial in achieving the desired performance benchmarks.

09

Key Results

78 words

Gemini 2.5 Pro achieved remarkable results on several benchmarks. It topped the LMSys Chatbot Arena leaderboard, demonstrating its superior conversational AI capabilities. The model scored 63.8% on the SWE-bench Verified coding tasks, showcasing its proficiency in technical applications. Additionally, it scored 86.7% on the GPQA Diamond test and 91.7% on AIME 2025, indicating its effectiveness in general purpose question answering and interactive AI tasks. These results highlight the model's versatility and performance across a wide range of scenarios.

10

Ablation Studies

68 words

Ablation studies were conducted to understand the contributions of various components in Gemini 2.5 Pro. Removing the 'Thinking Mode' resulted in a significant drop in reasoning performance, underscoring its importance in enhancing logical processing. Similarly, disabling 'Multimodal Input Support' reduced the model's ability to handle complex tasks requiring data integration from different formats. These studies confirmed the critical role of each component in achieving the model's overall performance.

11

What This Changed

73 words

Gemini 2.5 Pro's advancements have significantly influenced the AI field, setting new benchmarks for reasoning and multimodal capabilities. Its success has spurred competition among tech giants like Google and OpenAI to develop more advanced AI models. The model's versatility has opened up new possibilities for AI applications, from advanced chatbots to multimodal analytics platforms. These innovations have paved the way for more dynamic and high-performing AI solutions, transforming the landscape of AI development.

12

Limitations & Open Questions

55 words

Despite its advancements, Gemini 2.5 Pro has limitations. The model's performance is still constrained by computational resources, particularly when handling extremely large contexts. There are also challenges in fine-tuning the model for specific applications without extensive retraining. Open questions remain about optimizing the model's efficiency and exploring new architectures that can further enhance its capabilities.

13

Why You Should Care

75 words

For product managers and AI developers, Gemini 2.5 Pro represents a significant opportunity to leverage cutting-edge AI capabilities. Its advancements in reasoning and multimodal support enable the development of more intelligent and versatile AI applications. Whether in customer service, coding assistance, or creative industries, the model's capabilities can be harnessed to enhance user experiences and drive innovation in AI-driven solutions. Embracing these innovations will be crucial for staying competitive in the rapidly evolving AI landscape.

Experience It

Live Experiment

Gemini 2.5 Pro

See Gemini 2.5 Pro in Action

Experience how Gemini 2.5 Pro's step-by-step reasoning and multimodal input support transform AI responses. This matters because it demonstrates a significant leap in AI's ability to understand and process complex information.

Notice how Gemini 2.5 Pro provides more structured, detailed, and contextually rich responses by leveraging its advanced reasoning and multimodal capabilities.

Try an example — see the difference instantly

⌘↵ to run

How grounded is this content?

Metrics are computed from available source text only — abstract, summary, and impact fields ingested into this system. Full paper PDF is not ingested; numerical claims that originate from within the paper body will not appear in these scores.

Source Richness100%

8 of 8 content fields populated. More fields = better-grounded generation.

Source Depth~233 words

Total source text analyzed by the model. Includes extended deep-dive summary — high confidence.

Number Grounding5 / 5

Key statistics whose numeric values appear verbatim in ingested source text. Unverified stats may originate from the full paper body.

Quote Traceability3 / 3

Key passages whose significant vocabulary (≥4-char words) overlap ≥35% with source text. Measures lexical traceability, not semantic accuracy.

Methodology: Number grounding uses regex digit extraction against source text. Quote traceability uses token set intersection on content words stripped of stop-words. Neither metric validates semantic correctness or factual accuracy against the original paper. For full verification, cross-reference with the original paper via the arXiv link above.