Best AI Models for Microsoft 365 Copilot

ChatGPT by OpenAI is a versatile AI conversational platform that provides assistance in writing, learning, brainstorming, code generation, and problem-solving across a wide range of topics. Available for free with optional Plus and Pro subscription plans, it supports real-time text and voice interactions on web browsers and mobile apps. Users can leverage ChatGPT to create content, summarize meetings, debug code, analyze data, and even generate images using integrated tools like DALL·E 3. The platform is accessible via desktop and mobile devices and offers personalized workflows through custom GPTs and projects. Advanced plans unlock deeper research capabilities, extended limits, and access to cutting-edge AI models like GPT-4o and OpenAI o1 pro mode. ChatGPT integrates search capabilities for real-time information and enables collaboration through features like Canvas for project editing. It caters to students, professionals, hobbyists, and developers seeking efficient, AI-driven support. OpenAI continually updates ChatGPT with new tools and enhanced usability.

OpenAI aims to guarantee that artificial general intelligence (AGI)—defined as highly autonomous systems excelling beyond human capabilities in most economically significant tasks—serves the interests of all humanity. While we intend to develop safe and advantageous AGI directly, we consider our mission successful if our efforts support others in achieving this goal. You can utilize our API for a variety of language-related tasks, including semantic search, summarization, sentiment analysis, content creation, translation, and beyond, all with just a few examples or by clearly stating your task in English. A straightforward integration provides you with access to our continuously advancing AI technology, allowing you to explore the API’s capabilities through these illustrative completions and discover numerous potential applications.

Our models are designed to comprehend and produce natural language effectively. We provide four primary models, each tailored for varying levels of complexity and speed to address diverse tasks. Among these, Davinci stands out as the most powerful, while Ada excels in speed. The core GPT-3 models are primarily intended for use with the text completion endpoint, but we also have specific models optimized for alternative endpoints. Davinci is not only the most capable within its family but also adept at executing tasks with less guidance compared to its peers. For scenarios that demand deep content understanding, such as tailored summarization and creative writing, Davinci consistently delivers superior outcomes. However, its enhanced capabilities necessitate greater computational resources, resulting in higher costs per API call and slower response times compared to other models. Overall, selecting the appropriate model depends on the specific requirements of the task at hand.

GPT-4, or Generative Pre-trained Transformer 4, is a highly advanced unsupervised language model that is anticipated for release by OpenAI. As the successor to GPT-3, it belongs to the GPT-n series of natural language processing models and was developed using an extensive dataset comprising 45TB of text, enabling it to generate and comprehend text in a manner akin to human communication. Distinct from many conventional NLP models, GPT-4 operates without the need for additional training data tailored to specific tasks. It is capable of generating text or responding to inquiries by utilizing only the context it creates internally. Demonstrating remarkable versatility, GPT-4 can adeptly tackle a diverse array of tasks such as translation, summarization, question answering, sentiment analysis, and more, all without any dedicated task-specific training. This ability to perform such varied functions further highlights its potential impact on the field of artificial intelligence and natural language processing.

GPT-5.1 Pro is a premium, research-focused model tier built for users who need the strongest reasoning performance ChatGPT offers. It excels in technical domains such as advanced mathematics, scientific analysis, engineering, complex coding, and financial modeling. The model is engineered to deliver more coherent long-form reasoning, better chain-of-thought structure, and stronger factual grounding than general-purpose versions. With expanded context capacity, GPT-5.1 Pro handles large documents, multi-file analysis, and intricate workflows with ease. It also produces clearer explanations with reduced jargon, making complex insights more accessible without losing technical depth. Designed for demanding professional environments, Pro adheres to strict accuracy expectations while minimizing hallucinations in critical tasks. It is restricted to ChatGPT Pro and Business plans, ensuring dedicated access with no usage caps beyond standard abuse guardrails. Compared to other tiers, GPT-5.1 Pro is purpose-built for users who rely on ChatGPT as a high-precision analytical engine.

OpenAI’s GPT-5 represents the cutting edge in AI language models, designed to be smarter, faster, and more reliable across diverse applications such as legal analysis, scientific research, and financial modeling. This flagship model incorporates built-in “thinking” to deliver accurate, professional, and nuanced responses that help users solve complex problems. With a massive context window and high token output limits, GPT-5 supports extensive conversations and intricate coding tasks with minimal prompting. It introduces advanced features like the verbosity parameter, enabling users to control the detail and tone of generated content. GPT-5 also integrates seamlessly with enterprise data sources like Google Drive and SharePoint, enhancing response relevance with company-specific knowledge while ensuring data privacy. The model’s improved personality and steerability make it adaptable for a wide range of business needs. Available in ChatGPT and API platforms, GPT-5 brings expert intelligence to every user, from casual individuals to large organizations. Its release marks a major step forward in AI-assisted productivity and collaboration.

The latest iteration in the GPT-5 series, known as GPT-5.1, aims to significantly enhance the intelligence and conversational abilities of ChatGPT. This update features two separate model types: GPT-5.1 Instant, recognized as the most popular option, is characterized by a warmer demeanor, improved instruction adherence, and heightened intelligence; on the other hand, GPT-5.1 Thinking has been fine-tuned as an advanced reasoning engine, making it easier to grasp, quicker for simpler tasks, and more diligent when tackling complex issues. Additionally, queries from users are now intelligently directed to the model variant that is best equipped for the specific task at hand. This update not only focuses on boosting raw cognitive capabilities but also on refining the communication style, resulting in models that are more enjoyable to interact with and better aligned with users' intentions. Notably, the system card addendum indicates that GPT-5.1 Instant employs a feature called "adaptive reasoning," allowing it to determine when deeper thought is necessary before formulating a response, while GPT-5.1 Thinking adjusts its reasoning time precisely in relation to the complexity of the question posed. Ultimately, these advancements mark a significant step forward in making AI interactions more intuitive and user-friendly.

Phi-4-mini-flash-reasoning is a 3.8 billion-parameter model that is part of Microsoft's Phi series, specifically designed for edge, mobile, and other environments with constrained resources where processing power, memory, and speed are limited. This innovative model features the SambaY hybrid decoder architecture, integrating Gated Memory Units (GMUs) with Mamba state-space and sliding-window attention layers, achieving up to ten times the throughput and a latency reduction of 2 to 3 times compared to its earlier versions without compromising on its ability to perform complex mathematical and logical reasoning. With a support for a context length of 64K tokens and being fine-tuned on high-quality synthetic datasets, it is particularly adept at handling long-context retrieval, reasoning tasks, and real-time inference, all manageable on a single GPU. Available through platforms such as Azure AI Foundry, NVIDIA API Catalog, and Hugging Face, Phi-4-mini-flash-reasoning empowers developers to create applications that are not only fast but also scalable and capable of intensive logical processing. This accessibility allows a broader range of developers to leverage its capabilities for innovative solutions.

GPT-5.1 Instant is an advanced AI model tailored for everyday users, merging rapid response times with enhanced conversational warmth. Its adaptive reasoning capability allows it to determine the necessary computational effort for tasks, ensuring swift responses while maintaining a deep level of understanding. By focusing on improved instruction adherence, users can provide detailed guidance and anticipate reliable execution. Additionally, the model features expanded personality controls, allowing the chat tone to be adjusted to Default, Friendly, Professional, Candid, Quirky, or Efficient, alongside ongoing trials of more nuanced voice modulation. The primary aim is to create interactions that feel more organic and less mechanical, all while ensuring robust intelligence in writing, coding, analysis, and reasoning tasks. Furthermore, GPT-5.1 Instant intelligently manages user requests through the main interface, deciding whether to employ this version or the more complex “Thinking” model based on the context of the query. Ultimately, this innovative approach enhances user experience by making interactions more engaging and tailored to individual preferences.

GPT-5.1 Thinking represents an evolved reasoning model within the GPT-5.1 lineup, engineered to optimize "thinking time" allocation according to the complexity of prompts, allowing for quicker responses to straightforward inquiries while dedicating more resources to tackle challenging issues. In comparison to its earlier version, it demonstrates approximately double the speed on simpler tasks and takes twice as long for more complex ones. The model emphasizes clarity in its responses, minimizing the use of jargon and undefined terminology, which enhances the accessibility and comprehensibility of intricate analytical tasks. It adeptly modifies its reasoning depth, ensuring a more effective equilibrium between rapidity and thoroughness, especially when addressing technical subjects or multi-step inquiries. By fusing substantial reasoning power with enhanced clarity, GPT-5.1 Thinking emerges as an invaluable asset for handling complicated assignments, including in-depth analysis, programming, research, or technical discussions, while simultaneously decreasing unnecessary delays for routine requests. This improved efficiency not only benefits users seeking quick answers but also supports those engaged in more demanding cognitive tasks.