GPT-4o, OpenAI's third major iteration of GPT-4, introduces a unified multimodal architecture that handles text, vision, and audio within a single model rather than routing between separate specialized models. Released in May 2024, it is twice as fast, 50% cheaper, and offers 5x the rate limit compared to GPT-4 Turbo, with a 128K context window. The "omni" model enables near-zero latency voice interactions and native understanding across all supported modalities, including video input via frame extraction.

Roboflow's evaluation of GPT-4o across key computer vision tasks reveals meaningful improvements in some areas but persistent weaknesses in others. For OCR, GPT-4o achieves 94.12% average accuracy, a 10.8% improvement over GPT-4V, with a 58.47% speed increase making it the leader in speed efficiency. Document understanding also improved, successfully extracting tax information from receipts where GPT-4V had failed. However, object detection remains a significant weakness — GPT-4o fails to generate accurate bounding boxes, consistent with failures seen in Gemini, GPT-4V, and Claude 3 Opus. Visual question answering showed inconsistent counting ability, sometimes returning incorrect answers that change on retry.

The authors position GPT-4o as most valuable for rapid prototyping and scenarios where custom-trained or fine-tuned models aren't yet available. Its speed improvements finally open the door to real-time computer vision use cases, and its on-device multimodal capabilities reduce the friction of switching between screens and models. However, for specialized production applications, cost constraints and the lack of fine-tuning support mean that open-source and custom models remain preferable for many enterprise workflows.