List of the Top 25 Large Language Models for OpenAI Codex in 2026

ChatGPT is an advanced AI-powered assistant designed to help users accomplish tasks, generate ideas, and improve productivity across a wide range of use cases. It enables users to perform activities such as writing, editing, coding, research, and brainstorming with ease. The platform supports both text and voice interactions, allowing users to communicate in the way that suits them best. ChatGPT can summarize meetings, analyze data, and provide actionable insights to support better decision-making. It also assists with creative tasks, including content creation, marketing strategies, and personal planning. One of its most powerful capabilities is workspace agents, which allow users to build automated systems that handle entire workflows. These agents can operate across different tools, gather information, and take actions such as updating documents, sending communications, or managing tasks without constant supervision. They can be scheduled to run recurring processes, ensuring work continues even when teams are not actively involved. Workspace agents can be shared across teams, helping organizations standardize workflows and scale best practices efficiently. Built-in governance features, such as permissions, approval checkpoints, and monitoring, ensure secure and controlled automation. ChatGPT integrates seamlessly into existing workflows, reducing the need for multiple tools and manual coordination. It supports collaboration by allowing teams to refine, edit, and manage work in real time. The platform adapts to various industries and use cases, from personal productivity to enterprise operations. By combining intelligent assistance with automation, ChatGPT enables users to focus on higher-impact work. Ultimately, it acts as a comprehensive solution for both everyday tasks and complex organizational workflows.

Our models are crafted to understand and generate natural language effectively. We offer four main models, each designed with different complexities and speeds to meet a variety of needs. Among these options, Davinci emerges as the most robust, while Ada is known for its remarkable speed. The principal GPT-3 models are mainly focused on the text completion endpoint, yet we also provide specific models that are fine-tuned for other endpoints. Not only is Davinci the most advanced in its lineup, but it also performs tasks with minimal direction compared to its counterparts. For tasks that require a nuanced understanding of content, like customized summarization and creative writing, Davinci reliably produces outstanding results. Nevertheless, its superior capabilities come at the cost of requiring more computational power, which leads to higher expenses per API call and slower response times when compared to other models. Consequently, the choice of model should align with the particular demands of the task in question, ensuring optimal performance for the user's needs. Ultimately, understanding the strengths and limitations of each model is essential for achieving the best results.

The fourth iteration of the Generative Pre-trained Transformer, known as GPT-4, is an advanced language model expected to be launched by OpenAI. As the next generation following GPT-3, it is part of the series of models designed for natural language processing and has been built on an extensive dataset of 45TB of text, allowing it to produce and understand language in a way that closely resembles human interaction. Unlike traditional natural language processing models, GPT-4 does not require additional training on specific datasets for particular tasks. It generates responses and creates context solely based on its internal mechanisms. This remarkable capacity enables GPT-4 to perform a wide range of functions, including translation, summarization, answering questions, sentiment analysis, and more, all without the need for specialized training for each task. The model’s ability to handle such a variety of applications underscores its significant potential to influence advancements in artificial intelligence and natural language processing fields. Furthermore, as it continues to evolve, GPT-4 may pave the way for even more sophisticated applications in the future.

Muse Spark 1.1 is an advanced multimodal reasoning model from Meta Superintelligence Labs built for agentic work, coding, computer use, tool calling, and multimodal understanding. It is a major upgrade from Muse Spark and is designed to push the performance-efficiency frontier for AI systems that need to plan, reason, act, and coordinate across complex workflows. The model can operate across external apps, native tools, MCP servers, custom skills, browsers, scripts, images, videos, PDFs, audio, and developer environments. Muse Spark 1.1 is especially strong in agentic orchestration, where it can gather context, make plans, delegate work to parallel subagents, and manage execution across multiple steps. As a subagent, it can follow a defined role, use available tools appropriately, and escalate back to a main agent when needed. Its 1 million token context window helps it remember past actions, retrieve information from earlier in a project, and compact long sessions while keeping important details available for later work. For computer-use tasks, Muse Spark 1.1 can navigate unfamiliar interfaces, adapt to changing requirements, and choose whether to click through an interface or write scripts when automation is faster. In software engineering, the model can diagnose complex bugs, implement new features, perform large code migrations, build web applications, inspect screenshots, trace issues to code, and validate fixes. Its multimodal capabilities allow it to inspect visual and audio information, generate detailed image and video captions, create visual-to-code artifacts, and combine perception with action in practical workflows. Developers can access Muse Spark 1.1 through Meta’s new Model API public preview, and everyday users can try it in Thinking mode in the Meta AI app.

GPT-5.5 represents a new class of AI built to transform how work is done across digital environments. It combines advanced reasoning, tool usage, and task execution capabilities to manage complex, multi-step workflows with minimal human intervention. The model performs strongly in software engineering, data analysis, business operations, and scientific research, where it can plan tasks, gather information, test solutions, and refine outputs iteratively. It supports generating documents, building applications, analyzing large datasets, and navigating software systems as part of a unified workflow. A key capability is its integration with workspace agents—customizable AI agents that can be created once and deployed across teams to automate entire processes. These agents can run continuously, interact with tools like CRM systems, messaging platforms, and document editors, and keep workflows moving without constant supervision. Organizations can define permissions, approval checkpoints, and monitoring to maintain full control over automation. GPT-5.5 also improves collaboration by standardizing workflows and scaling best practices across teams. With enterprise-grade security and governance, it is designed for safe deployment in complex environments. Its ability to persist through ambiguity and long-running tasks makes it highly effective for execution-heavy work. By reducing manual intervention and increasing speed, GPT-5.5 enables teams to focus on higher-value activities and operate at a significantly higher level of productivity.

GPT-5.6 Terra is a balanced model in OpenAI’s GPT-5.6 series, designed to provide strong performance for everyday work while keeping costs lower than the flagship Sol tier. The GPT-5.6 family includes Sol for the highest capability, Terra for balanced work, and Luna for fast and affordable use cases. Terra is positioned as a practical option for developers, businesses, and enterprise teams that need capable reasoning, coding, automation, research support, and defensive security assistance without always using the most expensive model. According to the pasted preview text, Terra offers competitive performance to GPT-5.5 while being 2x cheaper. It appears in GPT-5.6 benchmark previews for Terminal-Bench 2.1, GeneBench v1, ExploitBench, and ExploitGym, showing that the model is intended for technical and long-horizon tasks as well as general work. Terra can support coding workflows that require planning, iteration, command-line reasoning, and tool coordination. It can also support legitimate cybersecurity workflows such as code review, vulnerability research, patch development, debugging, security education, and defensive testing. The model is developed with layered safeguards matched to its capabilities, including trained refusals, real-time checks, misuse classifiers, monitoring, enforcement, and account-level review. OpenAI also describes automated red-teaming and third-party human expert red-teaming as part of the broader GPT-5.6 safety process. Terra is priced below Sol in the pasted API pricing structure, with lower input and output costs per 1 million tokens. GPT-5.6 Terra helps organizations use a capable GPT-5.6 model for production workflows where performance, cost efficiency, and safety controls all matter.

GPT-5.6 Sol is a next-generation OpenAI model previewed as the flagship option in the GPT-5.6 family. The series includes Sol for the strongest capability, Terra for balanced everyday work, and Luna for faster, lower-cost use cases. GPT-5.6 Sol is built for demanding work across coding, agentic automation, biology, cybersecurity, research, and enterprise knowledge workflows. The model introduces a new max reasoning effort that allows it to spend more time reasoning through difficult problems. It also adds ultra mode, which coordinates subagents to help accelerate complex tasks that benefit from parallel or multi-agent execution. In coding workflows, GPT-5.6 Sol is designed for command-line tasks that require planning, iteration, testing, tool coordination, and long-horizon software engineering judgment. In biology workflows, it is positioned for genomics and quantitative-biology analysis where efficient reasoning over complex scientific tasks matters. In cybersecurity, GPT-5.6 Sol supports legitimate defensive work such as vulnerability discovery, patch development, debugging, security education, code review, and authorized testing. OpenAI describes GPT-5.6 Sol as more capable at helping users find and fix vulnerabilities than reliably carrying out end-to-end attacks under tested conditions. The model’s release is paired with a layered safeguard system that includes model-level refusals, real-time misuse classifiers, paused generation for higher-risk cases, account-level review, automated red-teaming, third-party testing, differentiated access, and enterprise safety controls. GPT-5.6 Sol helps developers, researchers, enterprises, and cyber defenders use frontier AI for advanced technical work while supporting safer deployment, stronger oversight, and phased access.

GPT-5.6 Luna is the lowest-cost model in OpenAI’s GPT-5.6 family, built for fast and affordable AI assistance across everyday and technical workflows. The GPT-5.6 lineup includes Sol as the flagship model, Terra as the balanced model for everyday work, and Luna as the efficient model for users who need strong capability at lower cost. Luna is intended for developers, businesses, and teams that need scalable AI for coding help, workflow automation, research support, analysis, customer-facing applications, and high-volume API usage. In the pasted preview text, Luna is presented as part of the same GPT-5.6 release process and benchmark set as Sol and Terra. It appears in evaluations for command-line coding workflows, long-horizon biology tasks, ExploitBench, and ExploitGym, indicating that it is designed to handle more than simple chat use cases. The model is priced at a lower per-token rate than Sol and Terra, making it more suitable for applications where cost efficiency is a major priority. GPT-5.6 Luna also supports the new GPT-5.6 prompt caching approach, including explicit cache breakpoints, a 30-minute minimum cache life, cache writes billed above the uncached input rate, and discounted cached-input reads. Like the rest of the GPT-5.6 family, Luna is developed with layered safeguards matched to model capability. These safeguards include trained refusals for prohibited cyber assistance, real-time misuse classifiers, paused generation for higher-risk cases, account-level review, monitoring, enforcement, automated red-teaming, and third-party human expert red-teaming. Luna is expected to support legitimate defensive and technical workflows such as code review, debugging, patch development, security education, and defensive testing while making prohibited misuse more difficult and detectable. GPT-5.6 Luna helps organizations deploy GPT-5.6-class AI where speed, affordability, scalability, and safe production use are the most important requirements.

Kimi K3 is Moonshot AI’s most advanced model, designed for high-end reasoning, software engineering, multimodal understanding, knowledge work, and agentic AI applications. The model has 2.8 trillion parameters and is built on Kimi Delta Attention, a hybrid linear attention mechanism created for long-context performance. It also uses Attention Residuals and supports a native context window of up to 1 million tokens. This makes Kimi K3 suitable for tasks involving large codebases, long research materials, enterprise documentation, multi-file analysis, legal documents, technical manuals, and complex workflows. Kimi K3 always has thinking mode enabled, with reasoning effort configured through the reasoning_effort field and maximum effort currently supported as the default. Developers can use the model through an OpenAI-compatible API, making it easier to integrate with existing SDKs, clients, and application infrastructure. The model supports streaming responses with separate reasoning and final-answer deltas, allowing applications to display reasoning progress and final content differently. Kimi K3 also supports strict structured output with JSON Schema, partial mode for continuing from a prefix, custom tool calling, required tool use, and dynamic tool loading through system messages. Its vision capabilities support image and video inputs through base64 or uploaded files, enabling analysis of visual content alongside text. Automatic context caching helps workflows that reuse long prefixes, such as large knowledge bases or persistent system context, without requiring developers to manage cache IDs manually. By combining frontier-scale parameters, long-context processing, visual input, structured outputs, tool orchestration, and developer-friendly API compatibility, Kimi K3 gives teams a strong foundation for advanced AI agents, coding assistants, research systems, enterprise automation, and multimodal applications.

Muse Spark is an advanced multimodal AI model developed by Meta Superintelligence Labs, representing a major step toward personal superintelligence. It is built from the ground up to integrate text, images, and tool-based interactions, enabling more dynamic and intelligent responses. The model features visual chain-of-thought reasoning, allowing it to process and explain visual information in a structured way. It also supports multi-agent orchestration, where multiple AI agents collaborate to solve complex problems efficiently. Muse Spark introduces Contemplating mode, which enhances reasoning by enabling parallel agent workflows for higher accuracy and performance. The model demonstrates strong capabilities in areas such as STEM reasoning, health analysis, and real-world problem-solving. It can generate interactive experiences, such as visual annotations, educational tools, and personalized insights. Muse Spark is trained using a combination of advanced pretraining, reinforcement learning, and optimized test-time reasoning strategies. Its architecture focuses on scaling efficiency, achieving strong performance with reduced computational requirements. Safety is a key priority, with built-in safeguards, alignment mechanisms, and robust evaluation processes. The model is available through Meta AI platforms, with API access in limited preview. Overall, Muse Spark represents a significant evolution in AI, moving closer to highly personalized, intelligent assistants that understand and interact with the real world.

GPT-5.1 Pro represents the top tier of OpenAI’s GPT-5 generation, delivering the most advanced reasoning, depth, and analytical intelligence available in ChatGPT. It is optimized for high-stakes, high-complexity scenarios where rigorous logic and verifiable accuracy are essential. Professionals use GPT-5.1 Pro for scientific research, large-scale codebases, legal reasoning, quantitative finance, data analysis, and multi-step decision workflows that exceed the capabilities of general models. With a significantly expanded context window, GPT-5.1 Pro can ingest and analyze long documents, datasets, transcripts, and multi-file projects in a single session. The model’s reasoning engine is tuned for deeper internal deliberation, enabling structured explanations, defensible conclusions, and clearer thought processes. GPT-5.1 Pro also features enhanced adherence to instructions, producing responses that are more predictable, consistent, and aligned with user goals. Compared to Instant and Thinking modes, it is built for reliability rather than speed, prioritizing quality of reasoning over quick output. While it supports most ChatGPT tools, it is intentionally restricted from Canvas and image generation to preserve dedicated compute for reasoning-heavy tasks. GPT-5.1 Pro is exclusive to ChatGPT Pro and Business subscribers, offering unlimited access within standard safety guardrails. It is the model tier best suited for users who depend on ChatGPT as a trusted research partner and analytical assistant.

Leverage advanced coding and linguistic models across a wide range of applications. Tap into the capabilities of extensive generative AI models that offer a profound understanding of both language and programming, facilitating innovative reasoning and comprehension essential for creating cutting-edge applications. These models find utility in various areas, such as writing assistance, code generation, and data analytics, all while adhering to responsible AI guidelines to mitigate any potential misuse, supported by robust Azure security measures. Utilize generative models that have been exposed to extensive datasets, enabling their use in multiple contexts like language processing, coding assignments, logical reasoning, inferencing, and understanding. Customize these generative models to suit your specific requirements by employing labeled datasets through an easy-to-use REST API. You can improve the accuracy of your outputs by refining the model’s hyperparameters and applying few-shot learning strategies to provide the API with examples, resulting in more relevant outputs and ultimately boosting application effectiveness. By implementing appropriate configurations and optimizations, you can significantly enhance your application's performance while ensuring a commitment to ethical practices in AI application. Additionally, the continuous evolution of these models allows for ongoing improvements, keeping pace with advancements in technology.

GPT-5 mini is a faster, more affordable variant of OpenAI’s advanced GPT-5 language model, specifically tailored for well-defined and precise tasks that benefit from high reasoning ability. It accepts both text and image inputs (image input only), and generates high-quality text outputs, supported by a large 400,000-token context window and a maximum of 128,000 tokens in output, enabling complex multi-step reasoning and detailed responses. The model excels in providing rapid response times, making it ideal for use cases where speed and efficiency are critical, such as chatbots, customer service, or real-time analytics. GPT-5 mini’s pricing structure significantly reduces costs, with input tokens priced at $0.25 per million and output tokens at $2 per million, offering a more economical option compared to the flagship GPT-5. While it supports advanced features like streaming, function calling, structured output generation, and fine-tuning, it does not currently support audio input or image generation capabilities. GPT-5 mini integrates seamlessly with multiple API endpoints including chat completions, responses, embeddings, and batch processing, providing versatility for a wide array of applications. Rate limits are tier-based, scaling from 500 requests per minute up to 30,000 per minute for higher tiers, accommodating small to large scale deployments. The model also supports snapshots to lock in performance and behavior, ensuring consistency across applications. GPT-5 mini is ideal for developers and businesses seeking a cost-effective solution with high reasoning power and fast throughput. It balances cutting-edge AI capabilities with efficiency, making it a practical choice for applications demanding speed, precision, and scalability.

GPT-5 nano is OpenAI’s fastest and most cost-efficient version of the GPT-5 model, engineered to handle high-speed text and image input processing for tasks such as summarization, classification, and content generation. It features an extensive 400,000-token context window and can output up to 128,000 tokens, allowing for complex, multi-step language understanding despite its focus on speed. With ultra-low pricing—$0.05 per million input tokens and $0.40 per million output tokens—GPT-5 nano makes advanced AI accessible to budget-conscious users and developers working at scale. The model supports a variety of advanced API features, including streaming output, function calling for interactive applications, structured outputs for precise control, and fine-tuning for customization. While it lacks support for audio input and web search, GPT-5 nano supports image input, code interpretation, and file search, broadening its utility. Developers benefit from tiered rate limits that scale from 500 to 30,000 requests per minute and up to 180 million tokens per minute, supporting everything from small projects to enterprise workloads. The model also offers snapshots to lock performance and behavior, ensuring consistent results over time. GPT-5 nano strikes a practical balance between speed, cost, and capability, making it ideal for fast, efficient AI implementations where rapid turnaround and budget are critical. It fits well for applications requiring real-time summarization, classification, chatbots, or lightweight natural language processing tasks. Overall, GPT-5 nano expands the accessibility of OpenAI’s powerful AI technology to a broader user base.

GPT-5.5 Pro represents a new class of AI designed to transform how work gets done across digital environments. It combines advanced reasoning, tool usage, and task execution capabilities to handle complex, multi-step workflows with minimal human intervention. The model excels in areas such as software engineering, data analysis, business operations, and scientific research, where it can plan tasks, gather information, test solutions, and refine outputs continuously. It supports creating applications, generating reports, building spreadsheets, and navigating software systems as part of a complete workflow. A key capability is its integration with workspace agents—custom AI agents that can be built once and deployed across teams to automate entire processes. These agents can run tasks on schedules, interact with tools like CRM systems, messaging platforms, and document editors, and keep workflows moving without constant supervision. Organizations can define permissions, approval checkpoints, and monitoring to maintain control over automated processes. GPT-5.5 Pro also enhances collaboration by enabling teams to standardize workflows and scale best practices across the organization. With enterprise-grade security and governance, it ensures safe deployment in complex environments. Its ability to persist through ambiguity and long tasks makes it highly effective for execution-heavy work. By reducing manual intervention and increasing speed, it allows teams to focus on higher-value activities. Ultimately, GPT-5.5 Pro enables businesses and professionals to operate at a significantly higher level of productivity and efficiency.

OpenAI’s GPT-5 is the latest flagship AI language model, delivering unprecedented intelligence, speed, and versatility for a broad spectrum of tasks including coding, scientific inquiry, legal research, and financial analysis. It is engineered with built-in reasoning capabilities, allowing it to provide thoughtful, accurate, and context-aware responses that rival expert human knowledge. GPT-5 supports very large context windows—up to 400,000 tokens—and can generate outputs of up to 128,000 tokens, enabling complex, multi-step problem solving and long-form content creation. A novel ‘verbosity’ parameter lets users customize the length and depth of responses, while enhanced personality and steerability features improve user experience and interaction. The model integrates natively with enterprise software and cloud storage services such as Google Drive and SharePoint, leveraging company-specific data to deliver tailored insights securely and in compliance with privacy standards. GPT-5 also excels in agentic tasks, making it ideal for developers building advanced AI applications that require autonomy and multi-step decision-making. Available across ChatGPT, API, and developer tools, it transforms workflows by enabling employees to achieve expert-level results without switching between different models. Businesses can trust GPT-5 for critical work, benefiting from its safety improvements, increased accuracy, and deeper understanding. OpenAI continues to support a broad ecosystem, including specialized versions like GPT-5 mini and nano, to meet varied performance and cost needs. Overall, GPT-5 sets a new standard for AI-powered intelligence, collaboration, and productivity.

The newest version in the GPT-5 lineup, referred to as GPT-5.1, seeks to greatly improve the cognitive and conversational skills of ChatGPT. This upgrade introduces two distinct model types: GPT-5.1 Instant, which has become the favored choice due to its friendly tone, better adherence to instructions, and enhanced intelligence; conversely, GPT-5.1 Thinking has been optimized as a sophisticated reasoning engine, facilitating easier comprehension, faster responses for simpler queries, and greater diligence when addressing intricate problems. Moreover, user inquiries are now smartly routed to the model variant that is most suited for the specific task, ensuring efficiency and accuracy. This update not only enhances fundamental cognitive abilities but also fine-tunes the style of interaction, leading to models that are more pleasant to engage with and more in tune with user desires. Importantly, the system card supplement reveals that GPT-5.1 Instant features a mechanism called "adaptive reasoning," which helps it recognize when deeper contemplation is warranted before crafting its reply, while GPT-5.1 Thinking precisely tailors its reasoning duration based on the complexity of the question asked. These innovations signify a considerable leap in the quest to make AI interactions more seamless, enjoyable, and user-centric, paving the way for future developments in conversational AI technology.

The Thinking variant of GPT-5.2 stands as the highest achievement in OpenAI's GPT-5.2 series, meticulously crafted for thorough reasoning and the management of complex tasks across a diverse range of professional fields and elaborate contexts. Key improvements to the foundational GPT-5.2 framework enhance aspects such as grounding, stability, and overall reasoning quality, enabling this iteration to allocate more computational power and analytical resources to generate responses that are not only precise but also well-organized and rich in context, particularly useful when navigating intricate workflows and multi-step evaluations. With a strong emphasis on maintaining logical coherence, GPT-5.2 Thinking excels in comprehensive research synthesis, sophisticated coding and debugging, detailed data analysis, strategic planning, and high-caliber technical writing, offering a notable advantage over simpler models in scenarios that assess professional proficiency and deep knowledge. This cutting-edge model proves indispensable for experts aiming to address complex challenges with a high degree of accuracy and skill. Ultimately, GPT-5.2 Thinking redefines the capabilities expected in advanced AI applications, making it a valuable asset in today's fast-evolving professional landscape.

The GPT-5.2 Instant model is a rapid and effective evolution in OpenAI's GPT-5.2 series, specifically designed for everyday tasks and learning, and it demonstrates significant improvements in handling inquiries, offering how-to assistance, producing technical documents, and facilitating translation tasks when compared to its predecessors. This latest model expands on the engaging conversational approach seen in GPT-5.1 Instant, providing clearer explanations that emphasize key details, which allows users to access accurate answers more swiftly. Its improved speed and responsiveness enable it to efficiently manage common functions like answering questions, generating summaries, assisting with research, and supporting writing and editing endeavors, while also incorporating comprehensive advancements from the wider GPT-5.2 collection that enhance reasoning capabilities, manage lengthy contexts, and ensure factual correctness. Being part of the GPT-5.2 family, this model enjoys the benefits of collective foundational enhancements that boost its reliability and performance across a range of daily tasks. Users will find that the interaction experience is more intuitive and that they can significantly decrease the time spent looking for information. Overall, the advancements in this model not only streamline processes but also empower users to engage more effectively with technology in their daily routines.

The latest iteration of OpenAI's GPT model family, known as GPT-5.2 Pro, emerges as the pinnacle of advanced AI technology, specifically crafted to deliver outstanding reasoning abilities, manage complex tasks, and attain superior accuracy for high-stakes knowledge work, inventive problem-solving, and enterprise-level applications. This Pro version builds on the foundational improvements of the standard GPT-5.2, showcasing enhanced general intelligence, a better grasp of extended contexts, more reliable factual grounding, and optimized tool utilization, all driven by increased computational power and deeper processing capabilities to provide nuanced, trustworthy, and context-aware responses for users with intricate, multi-faceted requirements. In particular, GPT-5.2 Pro is adept at handling demanding workflows, which encompass sophisticated coding and debugging, in-depth data analysis, consolidation of research findings, meticulous document interpretation, and advanced project planning, while consistently ensuring higher accuracy and lower error rates than its less powerful variants. Consequently, this makes GPT-5.2 Pro an indispensable asset for professionals who aim to maximize their efficiency and confidently confront significant challenges in their endeavors. Moreover, its capacity to adapt to various industries further enhances its utility, making it a versatile tool for a broad range of applications.

GPT-5 Pro is OpenAI’s flagship AI model built to deliver exceptional reasoning power and precision for the most complex and nuanced problems across numerous domains. Utilizing advanced parallel computing techniques, it extends the GPT-5 architecture to think longer and more deeply, resulting in highly accurate and comprehensive responses on challenging tasks such as advanced science, health diagnostics, coding, and mathematics. This model consistently outperforms its predecessors on rigorous benchmarks like GPQA and expert evaluations, reducing major errors by 22% and gaining preference from external experts nearly 68% of the time over GPT-5 thinking. GPT-5 Pro is designed to adapt dynamically, determining when to engage extended reasoning for queries that benefit from it while balancing speed and depth. Beyond its technical prowess, it incorporates enhanced safety features, lowering hallucination rates and providing transparent communication when limits are reached or tasks cannot be completed. The model supports Pro users with unlimited access and integrates seamlessly into ChatGPT’s ecosystem, including Codex CLI for coding applications. GPT-5 Pro also benefits from improvements in reducing excessive agreeableness and sycophancy, making interactions feel natural and thoughtful. With extensive red-teaming and rigorous safety protocols, it is prepared to handle sensitive and high-stakes use cases responsibly. This model is ideal for researchers, developers, and professionals seeking the most reliable, insightful, and powerful AI assistant. GPT-5 Pro marks a major step forward in AI’s ability to augment human intelligence across complex real-world challenges.

GPT-5.1 Instant is a cutting-edge AI model designed specifically for everyday users, combining quick response capabilities with a heightened sense of conversational warmth. Its ability to adaptively reason enables it to gauge the necessary computational effort for various tasks, ensuring that responses are both timely and deeply comprehensible. By emphasizing improved adherence to instructions, users can offer detailed information and expect consistent and reliable execution. Additionally, the model incorporates expanded personality controls that allow users to tailor the chat tone to options such as Default, Friendly, Professional, Candid, Quirky, or Efficient, with ongoing experiments aimed at refining voice modulation further. The primary objective is to foster interactions that feel more natural and less robotic, all while delivering strong intelligence in writing, coding, analysis, and reasoning tasks. Moreover, GPT-5.1 Instant adeptly handles user requests through its main interface, intelligently deciding whether to utilize this version or the more intricate “Thinking” model based on the specific context of the inquiry. Furthermore, this innovative methodology significantly enhances the user experience by making communications more engaging and personalized according to individual preferences, ultimately transforming how users interact with AI.

GPT-5.1 Thinking is an advanced reasoning model within the GPT-5.1 series, designed to effectively manage "thinking time" based on the difficulty of prompts, thus facilitating faster responses to simple questions while allocating more resources to complex challenges. When compared to its predecessor, this model boasts nearly double the efficiency for straightforward tasks and requires twice the time for more intricate inquiries. It prioritizes the clarity of its answers, steering clear of jargon and ambiguous terms, which significantly improves the understanding of complex analytical tasks. The model skillfully adjusts its depth of reasoning, striking a balance between speed and thoroughness, particularly when it comes to technical topics or inquiries requiring multiple steps. By combining powerful reasoning capabilities with improved clarity, GPT-5.1 Thinking stands out as an essential tool for managing complex projects, such as detailed analyses, coding, research, or technical conversations, while also reducing wait times for simpler requests. This enhancement not only aids users in need of quick solutions but also effectively supports those engaged in higher-level cognitive tasks, making it a versatile asset in various contexts of use. Overall, GPT-5.1 Thinking represents a significant leap forward in processing efficiency and user engagement.

GPT-5.2 ushers in a significant leap forward for the GPT-5 ecosystem, redefining how the system reasons, communicates, and interprets human intent. Built on an upgraded architecture, this version refines every major cognitive dimension—from nuance detection to multi-step problem solving. A suite of enhanced variants works behind the scenes, each specialized to deliver more accuracy, coherence, and depth. GPT-5.2 Instant is engineered for speed and reliability, offering ultra-fast responses that remain highly aligned with user instructions even in complex contexts. GPT-5.2 Thinking extends the platform’s reasoning capacity, enabling more deliberate, structured, and transparent logic throughout long or sophisticated tasks. Automatic routing ensures users never need to choose a model themselves—the system selects the ideal variant based on the nature of the query. These upgrades make GPT-5.2 more adaptive, more stable, and more capable of handling nuanced, multi-intent prompts. Conversations feel more natural, with improved emotional tone matching, smoother transitions, and higher fidelity to user intent. The model also prioritizes clarity, reducing ambiguity while maintaining conversational warmth. Altogether, GPT-5.2 delivers a more intelligent, humanlike, and contextually aware AI experience for users across all domains.

GPT-5.3 Instant is an upgraded conversational model built to improve the everyday ChatGPT experience through smoother dialogue and stronger reliability. Rather than focusing solely on benchmark gains, this release emphasizes subtle but impactful qualities such as tone, conversational flow, and contextual awareness. The update reduces unnecessary refusals and trims overly cautious disclaimers, allowing responses to feel more direct and useful. It applies improved judgment in sensitive areas, striking a better balance between safety and helpfulness. Web-assisted answers have been refined to prioritize synthesis and relevance over lengthy link compilations. The model is less likely to over-rely on search results and instead integrates them thoughtfully with its existing knowledge. Accuracy has improved substantially, with measurable decreases in hallucination rates both with and without web access. Internal evaluations show particular gains in higher-stakes areas like law, finance, and medicine. GPT-5.3 Instant also strengthens its writing capabilities, producing prose that feels more textured, immersive, and emotionally controlled. These enhancements support both practical problem-solving and creative expression within the same conversational framework. The overall goal is to preserve ChatGPT’s familiar personality while delivering a more polished and capable interaction. GPT-5.3 Instant is now available to all users in ChatGPT and to developers via the API, with legacy models scheduled for phased retirement.