OpenAI rolls out ChatGPT 5.5 Instant as the new default model for everyone
Source: Mashable Tech
Announcement
The company announced in a blog post on Tuesday that ChatGPT 5.5 Instant has begun rolling out to all users as the new default model for the popular AI chatbot. The new model is a follow‑up to GPT 5.5, which was released in April.
Availability
GPT‑5.5 Instant replaces 5.3 Instant, which will remain available for the next three months for paid users but will otherwise be sunsetted.
Comparison with Other Models
Unlike Claude Opus 4.7 from Anthropic and GPT‑5.5, which are only available to paid customers, GPT‑5.5 Instant is “available to everyone.” OpenAI says it should produce fewer hallucinations and better overall results for everyday ChatGPT usage.
“This update makes everyday interactions more useful and more enjoyable: stronger and tighter answers across subject areas, a more natural conversational tone, and better use of the context you’ve already shared when personalization can help,” the blog post said.
Performance Improvements
According to OpenAI, GPT‑5.5 Instant produced 52.5 % fewer hallucinated claims in internal testing than GPT‑5.3 on “high‑stakes” topics like law, finance, and medicine. In addition, the new model reduced inaccurate claims by 37.3 % on especially challenging conversations that users had flagged for factual errors.
Additional Capabilities
- Better at deciding when to use web search for a prompt.
- Improved analysis of image uploads.
- More concise answers while maintaining a personality in its responses.
- Enhanced understanding and referencing of context from a connected Gmail account and other integrations.
- Should avoid mentioning goblins unless absolutely necessary.
Disclosure: Ziff Davis, Mashable’s parent company, filed a lawsuit against OpenAI in April 2025, alleging it infringed Ziff Davis copyrights in training and operating its AI systems.