OpenAI has introduced a new version of its AI model — GPT-5.3 Instant, which is now available to ChatGPT users and developers via API.
This is reported by Business • Media
Main Improvements of GPT-5.3 Instant
GPT-5.3 Instant is designed to enhance the quality of communication and provide more accurate, natural, and relevant responses. Significant attention has been paid to reducing the number of so-called “hallucinations” in the model’s responses, as well as minimizing instances of excessive refusals to safe user queries. The updated model better distinguishes context, avoids unnecessary cautious phrasing, and aims for direct, clear dialogue.
OpenAI emphasized that the main changes pertain to three aspects:
- communication style,
- relevance of responses,
- and fluidity of dialogue.
Developers claim that GPT-5.3 Instant is less likely to hit dead ends in conversations, reduces unnecessary caveats, and avoids categorical statements.
“The model is already available to ChatGPT users and developers via API.”
Fewer Errors and Improved Information Handling
One of the main changes in GPT-5.3 Instant is the reduction in the frequency of refusals to safe questions and a decrease in cautious introductions. Now users can receive clearer and more practical answers without unnecessary warnings. Additionally, the model analyzes information from web sources more effectively, correlating it with its own knowledge and logic, allowing it to not just paraphrase what it finds but to explain the context and highlight the main points.
According to the company, the new version of the model shows a significant decrease in instances of hallucinations: during web searches, this rate dropped by 26.8%, and when working solely with internal knowledge, it decreased by 19.7%. In tests based on user feedback, the reductions were 22.5% and 9.6%, respectively.
Comparison of responses from GPT 5.2 and GPT 5.3. Data: OpenAI.
The GPT-5.3 Instant model has also improved in assisting with writing various texts: it formulates ideas more accurately, confidently edits texts, and creates expressive prose.
Importantly, the new model is already integrated into ChatGPT, and for developers, it is available under the name gpt-5.3-chat-latest via API. The previous version, GPT-5.2 Instant, will remain in the Legacy Models section for paid users for another three months and will be phased out on June 3, 2026.
As a reminder, OpenAI previously raised $110 billion in investments at a valuation of $730 billion.