Last refreshed 2026-06-15. Next refresh: weekly.
Why use GPT-5.3 Chat on OpenRouter?
OpenRouter offers GPT-5.3 Chat with pay-as-you-go pricing at $1.75/1M input tokens. OpenRouter is a multi-provider LLM aggregator offering unified API access to 300+ models from all major labs and emerging providers, with automatic failover for reliability.
Compare GPT-5.3 Chat across 3 providers to find the best fit for your use caseSetup recipe
Docs fallbackUse the provider REST API or SDKCreate a provider API keymodel: openai/gpt-5.3-chatopenai/gpt-5.3-chatRequest example
openai/gpt-5.3-chat.Gotchas
- Use provider model ID "openai/gpt-5.3-chat", not the LLMReference slug "gpt-5.3-chat".
Compare GPT-5.3 Chat Across Providers
| Provider | Input (per 1M) | Output (per 1M) |
|---|---|---|
| OpenAI API | $1.75 | $14.00 |
| Vercel AI Gateway | $1.75 | $14.00 |
| OpenRouter | $1.75 | $14.00 |
Pricing
| Type | Price (per 1M) |
|---|---|
| Input tokens | $1.75 |
| Output tokens | $14.00 |
Capabilities
About GPT-5.3 Chat
GPT-5.3's conversational model, marketed as GPT-5.3 Instant. Available via the OpenAI API as gpt-5.3-chat-latest and in Azure AI Foundry as gpt-5.3-chat preview. Released March 3, 2026 as an update to ChatGPT's default model with reduced hallucinations, anti-sycophancy alignment, and faster short-prompt responses. GPT-5.5 Instant succeeded it as ChatGPT's default model on May 5, 2026.
FAQ
What does GPT-5.3 Chat cost on OpenRouter?
On OpenRouter, GPT-5.3 Chat costs $1.75 per 1M input tokens and $14.0 per 1M output tokens.
What is the context window for GPT-5.3 Chat on OpenRouter?
GPT-5.3 Chat supports a 128k token context window on OpenRouter.
How does OpenRouter compare to other GPT-5.3 Chat providers?
GPT-5.3 Chat is available from 3 providers. The cheapest input pricing is $1.75/1M tokens from OpenAI API.
What API model ID do I use for GPT-5.3 Chat on OpenRouter?
Use the model ID openai/gpt-5.3-chat when calling OpenRouter's API.
Who created GPT-5.3 Chat?
GPT-5.3 Chat was created by OpenAI as part of the GPT-5.3 model family.
Is GPT-5.3 Chat open source?
GPT-5.3 Chat is not open source; the seed data lists it as proprietary.