GPT-5.5 Instant

by OpenAI

GPT-5.5 Instant is a model from OpenAI, released on May 5, 2026. It has a 400K-token context window and can generate up to 128K output tokens. API pricing is $5 per 1M input tokens and $30 per 1M output tokens. It ranks #73 of 220 models by Intelligence Score with a score of 32.1.

GPT-5.5 Instant is OpenAI's latest Instant model and the default ChatGPT model released on May 5, 2026. It improves factuality, everyday reasoning, image understanding, STEM answers, concision, conversational tone, and personalization over GPT-5.3 Instant. In the API, it is exposed through the chat-latest alias, which points to the latest Instant model used in ChatGPT.

Key specs

ProviderOpenAI
Release date2026-05-05
Licenseproprietary
Context window400K tokens
Max output128K tokens
Input price$5 / 1M tokens
Output price$30 / 1M tokens
Intelligence Score32.1

Quick answers

What is the context window of GPT-5.5 Instant?

GPT-5.5 Instant has a context window of 400K tokens, with a maximum output of 128K tokens per response.

How much does GPT-5.5 Instant cost?

GPT-5.5 Instant costs $5 per 1M input tokens and $30 per 1M output tokens through the API.

Is GPT-5.5 Instant open source?

No. GPT-5.5 Instant is a proprietary model from OpenAI (proprietary license).

When was GPT-5.5 Instant released?

OpenAI released GPT-5.5 Instant on May 5, 2026.

How does GPT-5.5 Instant compare to Claude Opus 5.5 (Reasoning)?

GPT-5.5 Instant scores 32.1 on the Intelligence Score versus 60.5 for Claude Opus 5.5 (Reasoning), the current #1. Input pricing is $5 vs $4 per 1M tokens.

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