OpenAI has rolled out GPT-5.3 Instant, updating the core model used across ChatGPT. The update improves conversational flow, response relevance, and tone in everyday interactions while strengthening factual accuracy and web-based answers.
It reduces unnecessary refusals and overly cautious phrasing in general and sensitive queries, reflects user feedback on clarity and usability, and improves writing flexibility while maintaining coherence, the company said.
Key Features: GPT-5.3 Instant
Reduced unnecessary refusals and disclaimers
GPT-5.3 Instant lowers instances where safe questions were previously declined. It minimizes defensive or moralizing preambles and provides direct answers when appropriate.
Improved web result synthesis
When using web search, the model balances online findings with internal reasoning. Instead of presenting long lists of links or loosely connected summaries, it prioritizes relevant context and surfaces key information upfront.
More consistent conversational tone
The update reduces exaggerated or overly declarative phrasing and avoids assumptions about user intent. It maintains a smoother, more neutral conversational style across interactions. Users can adjust response tone, including warmth and enthusiasm, within settings.
Improved factual accuracy
OpenAI evaluated GPT-5.3 Instant using two internal benchmarks:
- In higher-stakes domains such as medicine, law, and finance, hallucinations were reduced by 26.8% with web use and 19.7% without web access.
- In an evaluation based on user-flagged factual errors, hallucinations decreased by 22.5% with web use and 9.6% without web access.
These results indicate improved reliability across both web-assisted and internal knowledge responses.
Stronger writing capabilities
The model improves support for drafting fiction, refining passages, and generating expressive prose. It transitions between practical and creative tasks while maintaining clarity and structure.
Limitations
OpenAI said responses in some non-English languages, including Japanese and Korean, may still sound overly literal or less natural, and added that tone consistency and broader customization remain under development.
Availability
GPT-5.3 Instant has begun rolling out to all ChatGPT users, and API access is available under the name gpt-5.3-chat-latest. The company said updates for Thinking and Pro will arrive later. GPT-5.2 Instant will stay accessible to paid users under Legacy Models for three months before it is discontinued on June 3, 2026.