GPT-5.3 Instant
Proprietary
About
OpenAI's fast, efficient model for everyday tasks in the GPT-5 family (initially released March 3, 2026). Updated to v1.1 on March 16, 2026 with improved follow-up tone, more direct responses, better conversational flow, and reduced teaser-style phrasing based on user feedback.
Capabilities
MultimodalFunction CallingTool UseJSON Mode
API Versions
1.11.0