GPT-5.3 Chat delivers smoother conversations with better accuracy and fewer unnecessary refusals.
LLM Gateway routes requests to the best providers that are able to handle your prompt size and parameters.
GPT-5.3 Chat delivers smoother conversations with better accuracy and fewer unnecessary refusals. You can access it through LLM Gateway's OpenAI-compatible API with automatic provider routing, fallback, and cost analytics.
Pricing for GPT-5.3 Chat on LLM Gateway starts at $1.75 per million input tokens and $14.00 per million output tokens, depending on the provider. The pricing table above always reflects the current per-provider rates.
GPT-5.3 Chat supports a context window of up to 128,000 tokens on its largest provider deployment.
GPT-5.3 Chat is served by Azure, OpenAI through LLM Gateway. Requests are automatically routed to the best available provider, with fallback when a provider has issues.
GPT-5.3 Chat supports tool (function) calling, but not JSON output modes.
GPT-5.3 Chat was released on March 3, 2026.