OpenAI

o3

OpenAI

OpenAI's most powerful reasoning model that pushes the frontier across coding, math, science, visual perception, and more. Sets new state-of-the-art on benchmarks including Codeforces, SWE-bench, and MMMU. Features full tool access and can agentically use and combine every tool within ChatGPT.

o4-mini

OpenAI

A smaller model optimized for fast, cost-efficient reasoning. Achieves remarkable performance for its size and cost, particularly in math, coding, and visual tasks. It is the best-performing benchmarked model on AIME 2024 and 2025, with significantly higher usage limits than o3.

GPT-4.1 mini

OpenAI

Smaller version of GPT-4.1 optimized for coding and instruction following while maintaining the 1M token context window. Designed for applications requiring strong coding capabilities with better efficiency.

GPT-4.1 nano

OpenAI

Most compact version of GPT-4.1 family, optimized for efficiency while maintaining strong coding and instruction following capabilities. Designed for applications requiring low latency and cost.

GPT-4.1

OpenAI

Latest generation GPT model with massive 1M token context window and significant improvements in coding, reasoning, and multimodal understanding. Sets new state-of-the-art results on multiple benchmarks.

GPT-4.5

OpenAI

A research preview of OpenAI's largest and most capable GPT model to date. GPT-4.5 represents a significant advancement in scaling unsupervised learning, delivering broader world knowledge, dramatically reduced hallucinations (37.1% vs 61.8% for GPT-4o), and enhanced emotional intelligence for more natural human collaboration. Excels at creative tasks, writing assistance, and complex problem-solving with improved factual accuracy and nuanced understanding of user intent.

o1-mini

OpenAI

Faster, cost-efficient reasoning model optimized for coding and agentic applications. 80% cheaper than o1-preview with strong capabilities for complex problem-solving in tasks where context is provided within the prompt.

o1-preview

OpenAI

Large reasoning model with strong capabilities for solving hard problems through extended thinking. Designed to spend more time reasoning before responding, with enhanced performance in science, coding, and math.

o1

OpenAI

The o1 model series is trained with large-scale reinforcement learning to reason using chain-of-thought. OpenAI o1 is the next model in this series (previously OpenAI o1-preview), with advanced reasoning capabilities that provide new avenues for improving safety and robustness. The model can reason about safety policies in context when responding to potentially unsafe prompts, through deliberative alignment.

GPT-4o

OpenAI

GPT-4o ('o' for 'omni') is a multimodal model that accepts any combination of text, audio, image, and video inputs and generates text, audio, and image outputs. It matches GPT-4 Turbo performance on English text and code, with significant improvements for non-English languages. It responds to audio inputs in as little as 232 milliseconds (avg. 320ms), similar to human conversation response time. GPT-4o is 50% cheaper in the API than previous models and features superior vision and audio understanding capabilities.

GPT-4 Turbo

OpenAI

Improved version of GPT-4 with significantly expanded context window, more recent knowledge cutoff, and optimized performance. Designed for production applications with better cost efficiency than the base GPT-4.

GPT-3.5 Turbo 16K

OpenAI

Extended context version of GPT-3.5 Turbo with a 16K token context window. Optimized for chat applications with improved instruction following and reduced hallucinations compared to base GPT-3.5.

GPT-4

OpenAI

Fourth-generation GPT model, with greatly improved reasoning and multimodal capabilities (accepts text and images). Model size not publicly disclosed (rumored ~1.7 trillion parameters). Achieved human-level performance on many academic and professional benchmarks.

GPT-3.5 Turbo

OpenAI

OpenAI's public conversational AI based on GPT-3.5. Fine-tuned for dialogue via RLHF, leading to widespread adoption in late 2022. Marked the first widely accessible GPT-powered chatbot.

InstructGPT/GPT-3.5

OpenAI

Instruction-tuned version of GPT-3 (a.k.a GPT-3.5) refined via Reinforcement Learning from Human Feedback (RLHF). Powers the initial version of ChatGPT (Dec 2022). Optimized for following user instructions safely.

Codex

OpenAI

A GPT-3-descendent model fine-tuned on billions of lines of source code from publicly available sources, including code in public GitHub repositories. Powers GitHub Copilot for code autocompletion and demonstrated strong coding ability (solving ~28% of HumanEval at 12B params). Most capable in Python, but proficient in over a dozen languages including JavaScript, Go, Perl, PHP, Ruby, Swift, TypeScript, and Shell.

GPT-3

OpenAI

175B-parameter GPT series model that set new benchmarks in few-shot learning and text generation. Demonstrated impressive zero-shot capabilities across NLP tasks.

GPT-2

OpenAI

Generative Pre-trained Transformer 2 (GPT-2) is a large language model by OpenAI and the second in their foundational series of GPT models. It was pre-trained on a dataset of 8 million web pages (WebText) and was a direct scale-up of GPT-1 with a ten-fold increase in both parameter count and training dataset size. Initially partially withheld due to concerns about potential misuse, the full model was released in November 2019.

GPT-1

OpenAI

Generative Pre-trained Transformer 1 (GPT-1) was the first of OpenAI's large language models, demonstrating unsupervised pre-training with a 12-layer decoder-only Transformer. It introduced a two-stage training process leveraging the BookCorpus dataset and achieved improvements across various NLP tasks.