Best AI Models for OpenAI Codex - Page 2

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.

GPT-5.2 marks a new milestone in the evolution of the GPT-5 series, bringing heightened intelligence, richer context understanding, and smoother conversational behavior. The updated architecture introduces multiple enhanced variants that work together to produce clearer reasoning and more accurate interpretations of user needs. GPT-5.2 Instant remains the main model for everyday interactions, now upgraded with faster response times, stronger instruction adherence, and more reliable contextual continuity. For users tackling complex or layered tasks, GPT-5.2 Thinking provides deeper cognitive structure, offering step-by-step explanations, stronger logical flow, and improved endurance across long-form reasoning challenges. The platform automatically determines which model variant is optimal for any query, ensuring users always benefit from the most appropriate capabilities. These advancements reduce friction, simplify workflows, and produce answers that feel more grounded and intention-aware. In addition to intelligence upgrades, GPT-5.2 emphasizes conversational naturalness, making exchanges feel more intuitive and humanlike. Overall, this release delivers a more capable, responsive, and adaptive AI experience across all forms of interaction.

GPT-5.2-Codex is a next-generation coding model created to support advanced, agent-driven software development. Built on the GPT-5.2 architecture, it is fine-tuned specifically for real-world engineering tasks. The model excels at working across large codebases while preserving context over long sessions. It handles complex refactors, migrations, and multi-step implementations more reliably than previous Codex models. GPT-5.2-Codex demonstrates top-tier performance in realistic terminal environments. Enhanced tool-calling and improved factual accuracy make it suitable for production workflows. The model is also significantly stronger in cybersecurity-related tasks. It can assist with vulnerability research and defensive security analysis. GPT-5.2-Codex includes safeguards designed to support responsible deployment. It represents a major advancement in professional-grade coding AI.

GPT-5.3-Codex is a next-generation AI agent built to expand Codex beyond code writing into full-spectrum professional execution. It unifies advanced coding intelligence with reasoning, planning, and computer-use capabilities. The model delivers faster performance while handling more complex workflows across development environments. GPT-5.3-Codex can autonomously iterate on large projects while remaining interactive and steerable. It supports tasks such as debugging, deployment, performance optimization, and system monitoring. The model demonstrates state-of-the-art results across real-world coding benchmarks. It also excels at web development, generating production-ready applications from minimal prompts. GPT-5.3-Codex understands intent more effectively, producing stronger default designs and functionality. Its agentic nature allows it to operate like a collaborative teammate. This makes it suitable for both individual developers and large teams.

GPT-5.3-Codex-Spark is OpenAI’s first model purpose-built for real-time coding within the Codex ecosystem. Engineered for ultra-low latency, it can generate more than 1000 tokens per second when running on Cerebras’ Wafer Scale Engine hardware. Unlike larger frontier models designed for long-running autonomous tasks, Codex-Spark specializes in rapid iteration, targeted edits, and immediate feedback loops. Developers can interrupt, redirect, and refine outputs interactively, making it ideal for collaborative coding sessions. The model features a 128k context window and is currently text-only during its research preview phase. End-to-end latency improvements—including WebSocket streaming and inference stack optimizations—reduce time-to-first-token by 50% and overall roundtrip overhead by up to 80%. Codex-Spark performs strongly on benchmarks such as SWE-Bench Pro and Terminal-Bench 2.0 while completing tasks significantly faster than its larger counterpart. It is available to ChatGPT Pro users in the Codex app, CLI, and VS Code extension with separate rate limits during preview. The model maintains OpenAI’s standard safety training and evaluation protocols. Codex-Spark represents the beginning of a dual-mode Codex future that blends real-time interaction with long-horizon reasoning capabilities.

GPT-5.3 Instant represents a significant refinement of ChatGPT’s core conversational model, prioritizing smoother, more natural interactions. This update directly addresses user feedback about tone, unnecessary refusals, and overly defensive disclaimers. The model now provides more direct answers when safe to do so, minimizing conversational friction and reducing dead ends. It also demonstrates improved judgment when handling sensitive topics, offering balanced responses without moralizing preambles. When using web information, GPT-5.3 Instant better synthesizes search results with its internal knowledge, delivering concise and relevant insights instead of link-heavy summaries. Internal evaluations show meaningful reductions in hallucination rates, particularly in high-stakes domains such as medicine, law, and finance. The model is designed to feel consistent and familiar while offering noticeable capability upgrades. Writing performance has been enhanced, enabling richer storytelling and more expressive prose without sacrificing clarity. These improvements aim to make ChatGPT feel less mechanical and more intuitively helpful in everyday use. GPT-5.3 Instant is available across ChatGPT and through the API, with older versions remaining temporarily accessible before retirement.

GPT-5.4 Pro is a high-performance AI model introduced by OpenAI for users who require maximum capability when solving complex problems. It builds on earlier GPT models by integrating advanced reasoning, coding, and workflow automation into a single system. The model is designed to assist professionals with demanding tasks such as data analysis, financial modeling, document generation, and software development. GPT-5.4 Pro can interact directly with computers and applications, allowing AI agents to perform multi-step workflows across different tools and environments. Its extended context window supports up to one million tokens, enabling it to analyze large amounts of information while maintaining accuracy. The model also improves deep web research and long-form reasoning tasks. Developers benefit from improved tool usage and search capabilities that help agents select and operate external tools efficiently. GPT-5.4 Pro delivers stronger coding performance and faster iteration cycles for developers working on complex software projects. It also reduces token usage compared with earlier models, improving cost efficiency and speed. Overall, GPT-5.4 Pro is designed to support advanced professional workflows and AI-powered automation at scale.

GPT-5.4 Thinking is a specialized version of OpenAI’s GPT-5.4 model designed to deliver enhanced reasoning and structured problem-solving in ChatGPT. It integrates improvements in coding, professional knowledge work, and agent-based workflows into a single AI system. One of its key features is the ability to present a plan for its reasoning before generating a final answer. This allows users to review the direction of the response and make adjustments while the model is still working. By enabling this interactive process, GPT-5.4 Thinking helps produce more precise and relevant results. The model is particularly effective for tasks that require deep research or multi-step reasoning. It also maintains context across longer prompts and conversations, reducing confusion in complex discussions. GPT-5.4 Thinking improves how AI interacts with tools and software environments during problem-solving workflows. Its advanced reasoning capabilities allow it to handle analytical tasks with higher consistency and clarity. As a result, GPT-5.4 Thinking is designed to support professionals who need reliable AI assistance for complex work.

GPT-5.4 mini is an advanced AI model designed to provide a balance between high performance, speed, and cost efficiency. It is built to handle a wide range of tasks, including coding, reasoning, tool usage, and multimodal understanding. Compared to earlier versions, GPT-5.4 mini delivers significantly improved performance while operating at faster speeds. The model is particularly effective in environments where low latency is essential, such as real-time coding assistants and interactive applications. It supports capabilities like function calling, tool integration, and image-based reasoning, making it highly versatile. GPT-5.4 mini is also well-suited for subagent architectures, where it can efficiently process smaller tasks within larger AI systems. Developers can use it to automate workflows, analyze data, and build responsive AI-driven applications. Its strong performance across benchmarks shows that it approaches the capabilities of larger models in many scenarios. At the same time, it maintains a lower cost, making it ideal for high-volume usage. Overall, GPT-5.4 mini provides a powerful and scalable solution for modern AI development.

GPT-5.4 nano is a compact and cost-efficient AI model designed for handling lightweight, high-frequency tasks at scale. It is optimized for operations such as classification, data extraction, ranking, and simple coding assistance. The model delivers fast response times, making it suitable for applications where low latency is critical. Compared to earlier nano models, GPT-5.4 nano offers improved performance while maintaining minimal computational cost. It supports key features such as tool usage and structured output generation, allowing it to integrate easily into automated systems. The model is often used as a subagent within larger AI workflows, handling repetitive or supporting tasks efficiently. This approach allows more complex models to focus on higher-level reasoning and decision-making. GPT-5.4 nano is particularly useful in environments that require processing large volumes of requests quickly. Its efficiency makes it ideal for cost-sensitive applications and scalable deployments. Overall, it provides a reliable and fast solution for simple AI-driven tasks.

SubQ is an advanced large language model created by Subquadratic to handle complex long-context reasoning tasks. It supports up to 12 million tokens in a single input, making it capable of analyzing entire repositories, extended conversation histories, and large datasets without losing context. The model is built on a sub-quadratic sparse-attention architecture that focuses computational resources on the most relevant data relationships. This design significantly reduces processing requirements compared to traditional transformer models while maintaining strong performance. SubQ is particularly useful for software engineering, coding workflows, and long-context retrieval tasks. It enables developers and teams to process large amounts of information in a single operation instead of splitting tasks into smaller parts. The model offers fast processing speeds and operates at a fraction of the cost of many competing solutions. It is available through API access, allowing integration into enterprise systems and developer tools. SubQ can also be used as a layer within coding agents to improve code exploration and analysis. Its compatibility with existing development environments makes it easier to adopt. With its efficient architecture and large context window, it helps teams work with complex data more effectively.

SubQ 1.1 Small is the second iteration of Subquadratic’s long-context AI model, built to help enterprises solve problems that require reasoning across entire artifacts rather than isolated chunks. The model is designed for use cases involving large code repositories, document libraries, legal agreements, financial reports, contracts, and other complex information sets. Its Subquadratic Sparse Attention architecture reduces the compute burden of traditional dense attention, making it more practical to process multi-million-token contexts. SubQ 1.1 Small achieves near-perfect performance on needle-in-a-haystack retrieval tests up to 12M tokens, despite being trained primarily at 1M tokens. It also performs strongly on RULER, GPQA Diamond, LiveCodeBench, and AutomationBench Finance, showing a balance between long-context retrieval and general reasoning ability. At 1M tokens, the model uses 64.5x less compute than dense attention and runs 56x faster than FlashAttention-2 on a single attention layer. This efficiency makes long-context training and inference more scalable for enterprise AI applications. SubQ 1.1 Small is especially valuable for teams that need to analyze relationships across full documents, trace logic across codebases, or connect information across extensive collections. The model is intended to help organizations reduce dependence on complex retrieval workarounds and reason more directly over large-scale data.

GPT-5.4 is a next-generation AI model created by OpenAI to assist professionals with advanced knowledge work and software development tasks. It brings together major improvements in reasoning, coding, and automated workflows to deliver more capable and reliable results. The model can analyze large datasets, generate detailed reports, create presentations, and assist with spreadsheet modeling. GPT-5.4 also supports complex coding tasks and can help developers build, test, and debug software more efficiently. One of its key advancements is the ability to use tools and interact with software environments to complete multi-step processes. The model supports very large context windows, allowing it to analyze long documents and maintain context across extended conversations. GPT-5.4 also improves web research capabilities by searching and synthesizing information from multiple sources more effectively. Enhanced accuracy reduces hallucinations and helps produce more reliable responses for professional use. The model is available through ChatGPT, developer APIs, and coding environments such as Codex. By combining reasoning, tool usage, and large-scale context understanding, GPT-5.4 enables users to automate complex workflows and produce high-quality outputs.

ChatGPT Images 2.0 is an advanced AI-powered image generation model created by OpenAI to deliver more accurate and practical visual outputs. It introduces a reasoning-based approach, allowing the system to plan and interpret prompts before generating images. This results in improved accuracy, better composition, and more consistent visual details. The platform excels at rendering text within images, supporting multilingual typography with high precision. It can generate multiple related images from a single prompt while maintaining consistency across characters and scenes. The model supports higher resolutions and flexible aspect ratios, making it suitable for professional use cases. ChatGPT Images 2.0 is designed for real-world applications such as marketing, presentations, storyboards, and product visuals. It also integrates with ChatGPT, making image creation part of a broader workflow. Compared to earlier versions, it provides more reliable outputs with fewer distortions or errors. The system can handle complex layouts, including infographics and UI designs. By combining reasoning, accuracy, and flexibility, ChatGPT Images 2.0 represents a major step forward in AI-generated visuals.