The GPT 4.1 family of models, including GPT 4.1, Mini, and Nano, has been launched in the API, offering significant improvements over GPT-4o in areas such as coding, instruction following, and long context handling, now supporting up to one million tokens. These models are also more cost-effective, with GPT 4.1 being 26% cheaper than GPT-4o, and include the Nano model as the smallest, fastest, and cheapest option ever offered