OpenAI's GPT-5.5 Instant Model Updated with Improved Shopping and Constraint Handling

OpenAI has updated its widely used language model, GPT-5.5 Instant, which is the default in the free version of ChatGPT. The company announced the upgraded version on X, calling it 'much more fun to talk to' and saying it is 'better at understanding the intent behind a question and adapting its response accordingly,' as well as offering improvements in shopping results, local recommendations, and handling 'complex constraints.' However, it has not yet provided any benchmarks or numerical results to quantify these claims. The updated GPT-5.5 Instant was rolling out first to paid ChatGPT subscribers and then to free users as of June 25.

OpenAI also updated its chat-latest API alias, which points to the latest GPT-5.5 Instant model currently used in ChatGPT, while continuing to recommend the separate gpt-5.5 model for production API usage. GPT-5.5 Instant was first unveiled in early May 2024, just under two months ago, to replace the aging GPT-5.3 Instant engine as the baseline default model for ChatGPT users. Developed as a fast, high-throughput variant of OpenAI’s core flagship model family, the initial spring release focused heavily on correcting systemic factuality deficits.

Internal benchmarks from that spring deployment reported a 52.5% reduction in hallucinated claims compared to GPT-5.3 Instant on high-stakes medical, legal, and financial prompts, alongside a 37.3% drop in factual error rates on user-flagged historical conversations. Independent evaluators noted that its predecessor, GPT-5.3 Instant, had struggled in public rankings, placing 44th overall in Arena benchmarks. The June 24 update does not appear to expand memory sources directly.

Instead, it focuses on making GPT-5.5 Instant better at understanding user intent, carrying context across turns, following multi-part instructions, and producing more useful shopping and local recommendations. A smarter, more 'fun' ChatGPT for consumers will be the most noticeable change in GPT-5.5 Instant. The model’s improved intent recognition will help identify the underlying goal behind a user's question, particularly in decision-support scenarios like planning, shopping, asking for advice, researching options and comparing local choices.

Developers can test the latest Instant behavior through chat-latest. For the developer ecosystem, the June 24 GPT-5.5 Instant update is accessible through OpenAI’s updated chat-latest API alias. chat-latest points to the latest Instant model currently used in ChatGPT, and it recommends the separate gpt-5.5 model for production API usage.

Developers can use chat-latest to test the newest ChatGPT-style improvements, while using gpt-5.5 when they need a stable production target. Why this matters: The updated GPT-5.5 Instant model has significant implications for both consumers and enterprises. With improved shopping results and complex constraint handling, ChatGPT becomes more useful for everyday decision-making.