GPT-4o is OpenAI's flagship multimodal model released in May 2024, combining strong general reasoning with native support for text, images, audio, and lightweight video. It matches or exceeds prior GPT-4-class models on benchmarks like MMLU while running roughly twice as fast and at lower cost, making it a practical default for many production workloads. GPT-4o is particularly strong at following complex instructions, maintaining coherent and emotionally-aware dialogue over long contexts, and delivering solid creative writing without sacrificing reliability.