GPT 5.3 Chat
by OpenAI
GPT-5.3 Chat is ChatGPT's default everyday conversation model delivering more accurate answers, richer web search results, and reduced hallucination rates by ~27% with web search and ~20% on internal knowledge vs prior models.
- ChatGPT's default everyday conversation model optimized for natural, smooth interactions.
- 128,000-token context window with 16,384 max output tokens for conversational use cases.
- Reduces hallucination rates by ~27% with web search and ~20% on internal knowledge.
- Supports streaming, function calling, and structured outputs for developer integration.
- Pricing is $1.75 per 1M input tokens and $14 per 1M output tokens (cached input at $0.175).
Web Search
Search the web for current info.
JSON Mode
Output responses in valid JSON format.
Image Generator
Generate images from text prompts.
Model Information
Supported Formats
GPT 5.5OpenAI's most advanced model released April 2026. GPT-5.5 is recommended for most reasoning workloads, combining frontier intelligence with configurable reasoning effort (none → xhigh). Available in API, Codex, and ChatGPT.
GPT 5.5 ProHighest-intelligence API option in the GPT-5.5 family. Use for the most challenging problems that require maximum reasoning depth and can tolerate higher latency. Supports full reasoning effort range from none to xhigh.
GPT 5.4GPT-5.4 is OpenAI's frontier model for complex professional work, designed for agentic, coding, and professional workflows with the highest reasoning capability. Features a 1.05M token context window, native computer use, and built-in support for web search, file search, and MCP.