Best Large Language Models for OpenAI Codex - Page 2

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.