OpenAI Releases GPT-5.3 Instant for ChatGPT, Reduces Hallucinations and Refusals

OpenAI has released GPT-5.3 Instant to all ChatGPT users, updating its most widely used model with changes aimed at improving everyday conversations. The company says the release focuses on tone, relevance, conversational flow, and how the model synthesizes information from the web.



One of the biggest adjustments is how the model handles refusals. Users had reported that GPT-5.2 Instant would sometimes decline questions it could safely answer, or add overly cautious disclaimers that interrupted the flow of conversation. OpenAI says GPT-5.3 Instant cuts back on those unnecessary refusals and defensive preambles. OpenAI says GPT-5.3 Instant significantly reduces unnecessary refusals and tones down defensive or moralizing preambles. When a useful answer is appropriate, the model now provides it directly without unnecessary caveats.


Search performance has also been improved. GPT-5.3 Instant is designed to better balance live web results with its own reasoning, using context to frame recent news rather than simply summarizing search links. OpenAI says the model is less likely to overindex on web results and does a stronger job recognizing the subtext of prompts, surfacing the most relevant details upfront.



The conversational tone has been refined as well. OpenAI trained the model to avoid phrasing users described as overbearing or awkward, aiming for a smoother and more natural style. The company says it is also working to keep ChatGPT's personality more consistent across updates. Users can still adjust traits such as warmth and enthusiasm within the app's settings.

Accuracy improvements are a key part of the release. In internal evaluations covering higher-stakes domains such as medicine, law, and finance, GPT-5.3 Instant reduced hallucination rates by 26.8 percent when using web access and 19.7 percent when relying solely on internal knowledge. In a separate evaluation based on de-identified user conversations previously flagged for factual errors, hallucinations decreased by 22.5 percent with web use and 9.6 percent without web access.

OpenAI also says GPT-5.3 Instant is a stronger writing partner, better able to shift between practical tasks and more expressive, imaginative prose without losing clarity.


There are still limitations. OpenAI notes that tone in some non-English languages, including Japanese and Korean, can sound overly literal. The company says refinements to tone and customization remain ongoing.

The updated model is available immediately in the iOS and Mac apps. This comes as ChatGPT expands its presence across Apple platforms, including support for running natively on the CarPlay dashboard in upcoming iOS updates and operating alongside the new Codex app for Mac.

GPT-5.3 Instant is available today for all users, including those on the free tier and the recently launched ChatGPT Go subscription. Developers can access it through the API as "gpt-5.3-chat-latest." GPT-5.2 Instant will remain available for paid users in the Legacy Models section for three months before being retired on June 3, 2026.