GPT-5 is the fifth and current flagship model of the generative pre-trained transformers (GPT) from OpenAI. It was introduced on August 7, 2025 and represents a further development of the predecessor models, including GPT-4 and its variants. GPT-5 is a multimodal large language model that can process and generate text, images and audio content.
Definition and architecture of GPT-5
GPT-5 is a comprehensive system designed to integrate both rational and non-rational functions under a unified user interface. A key innovation is the real-time router, which automatically decides whether to use a fast, high-throughput model for routine queries or a more in-depth „thinking model“ for complex thought processes. This eliminates the need for users to manually switch between specialized models.
The model was trained from scratch as a native multimodal system, meaning that it was developed simultaneously with different data modalities such as text and images, rather than building on already trained speech or vision models. The training process included unsupervised pre-training, supervised fine-tuning and reinforcement learning using human feedback.
Key features and performance
GPT-5 offers a number of significant improvements and new functions:
- Advanced thinking skills: The model shows a significantly improved ability to solve multi-step problems, interpret ambiguous questions and provide detailed reasoning for its answers. It can perform extended logical chains and decide independently when quick action or in-depth thinking is required.
- Extended multimodality: GPT-5 can process not only text, but also images and audio as input and generate corresponding output. This enables more complex interactions and applications.
- Reduced hallucinations: Compared to previous models, GPT-5 has a drastically lower rate of hallucinations in fact-based tasks. When web search is enabled, the probability of factual errors is reduced by 45 % compared to GPT-4o, and in thinking mode, error rates are reduced by as much as 80 % compared to previous thinking models.
- Longer context window: For API users, GPT-5 supports a combined input and output context length of up to 400,000 tokens. This enables the processing of larger documents and longer conversations.
- Improved programming skills: The model achieves a performance of 74.9 % on benchmarks such as SWE-bench Verified and 88 % on Aider Polyglot. It is more efficient than previous models and requires 22 % fewer output tokens and 45 % fewer tool calls at high thinking intensity to achieve similar results.
- Agent functions: GPT-5 can independently set up a desktop and use a browser to independently research relevant sources for a task.
- Availability: GPT-5 is for all ChatGPT-users as a standard model and accessible to developers via the OpenAI API. There are different variants such as
gpt-5,gpt-5-miniandgpt-5-nano, which are optimized for different requirements in terms of speed, costs and depth of thought.
