Why use GPT-5.5 Instant on OpenAI API?
OpenAI API offers GPT-5.5 Instant with pay-as-you-go pricing at $1.50/1M input tokens. OpenAI is a leading AI research and deployment company dedicated to developing safe and beneficial artificial general intelligence (AGI) for humanity.
Pricing
| Type | Price (per 1M) |
|---|---|
| Input tokens | $1.50 |
| Output tokens | $6.00 |
Capabilities
About GPT-5.5 Instant
GPT-5.5 Instant is OpenAI's latest Instant model used in ChatGPT, released May 5, 2026 as the new default ChatGPT model and exposed in the API as chat-latest. OpenAI says the update improves factuality, image analysis, STEM answers, web-search decisions, personalization from past chats/files/connected Gmail, and concise conversational style. OpenAI reports 52.5% fewer hallucinated claims than GPT-5.3 Instant on high-stakes prompts and 37.3% fewer inaccurate claims on difficult conversations flagged for factual errors.
FAQ
What does GPT-5.5 Instant cost on OpenAI API?
On OpenAI API, GPT-5.5 Instant costs $1.50 per 1M input tokens and $6.00 per 1M output tokens.
What is the context window for GPT-5.5 Instant on OpenAI API?
GPT-5.5 Instant supports a 400,000 token context window on OpenAI API.
What API model ID do I use for GPT-5.5 Instant on OpenAI API?
Use the model ID chat-latest when calling OpenAI API's API.
Who created GPT-5.5 Instant?
GPT-5.5 Instant was created by OpenAI as part of the GPT-5.5 model family.
Is GPT-5.5 Instant open source?
GPT-5.5 Instant is not open source; the seed data lists it as proprietary.