What are the major updates in GPT-4 compared to GPT-3?

GPT-4 introduces several key improvements over GPT-3, focusing on enhanced performance, broader capabilities, and better alignment with user intent. These updates address limitations in GPT-3 while expanding practical applications for developers. The changes can be grouped into three main areas: model architecture, input handling, and safety/accuracy.

First, GPT-4 uses a more advanced architecture that supports significantly larger context windows. While GPT-3 processed up to 4,096 tokens (roughly 3,000 words), GPT-4 extends this to 32,768 tokens in its largest configuration. This allows developers to input longer documents, maintain coherent multi-turn conversations, or analyze complex codebases without losing context. For example, a developer could feed an entire API documentation page into GPT-4 and ask it to generate sample code, whereas GPT-3 might struggle to retain all details. Additionally, GPT-4’s training data includes more recent information (up to September 2023, compared to GPT-3’s 2021 cutoff), improving its ability to discuss current technologies or frameworks.

Second, GPT-4 improves input flexibility and output control. It natively supports multimodal inputs, accepting both text and images (though image inputs are not yet publicly available via API). This opens possibilities like describing diagrams or extracting text from screenshots. For text-based workflows, GPT-4 handles ambiguous instructions better by asking clarifying questions when prompts are unclear. Developers can also use system-level “role” definitions (e.g., “act as a Python expert”) to steer outputs more precisely. In testing, GPT-4 demonstrates better task prioritization—when asked to debug code while explaining steps, it maintains focus on the primary goal instead of diverging into tangential explanations, a common issue with GPT-3.

Finally, GPT-4 emphasizes safety and factual accuracy. It reduces “hallucinations” (incorrect but confident-sounding answers) by 40% compared to GPT-3.5, according to OpenAI’s benchmarks. For developers, this means fewer cases of GPT-4 inventing nonexistent API endpoints or misrepresenting library functions. The model also integrates stronger content moderation tools, refusing harmful requests more consistently while allowing legitimate technical queries. For instance, GPT-4 will reject prompts asking for exploit code but still assist with security vulnerability analysis if phrased responsibly. These upgrades make GPT-4 more reliable for production use cases like documentation generation or automated code reviews, where accuracy and safety are critical.