GPT-5.6 Terra (Reasoning)

by OpenAI

GPT-5.6 Terra (Reasoning) is a reasoning model from OpenAI, released on July 9, 2026. It has a 1.1M-token context window and can generate up to 128K output tokens. API pricing is $2 per 1M input tokens and $12 per 1M output tokens. It ranks #19 of 220 models by Intelligence Score with a score of 49.4.

GPT-5.6 Terra is the balanced tier of OpenAI's GPT-5.6 family, designed for workloads that balance intelligence and cost. It delivers performance competitive with GPT-5.5 at roughly half the price, supports max reasoning effort, and has a 1.05M-token context window.

Key specs

ProviderOpenAI
Release date2026-07-09
Licenseproprietary
Context window1.1M tokens
Max output128K tokens
Input price$2 / 1M tokens
Output price$12 / 1M tokens
Intelligence Score49.4
Coding index39.9
Output speed125 tokens/s
Time to first token2.54 s

Quick answers

What is the context window of GPT-5.6 Terra (Reasoning)?

GPT-5.6 Terra (Reasoning) has a context window of 1.1M tokens, with a maximum output of 128K tokens per response.

How much does GPT-5.6 Terra (Reasoning) cost?

GPT-5.6 Terra (Reasoning) costs $2 per 1M input tokens and $12 per 1M output tokens through the API.

Is GPT-5.6 Terra (Reasoning) open source?

No. GPT-5.6 Terra (Reasoning) is a proprietary model from OpenAI (proprietary license).

When was GPT-5.6 Terra (Reasoning) released?

OpenAI released GPT-5.6 Terra (Reasoning) on July 9, 2026.

How does GPT-5.6 Terra (Reasoning) compare to Claude Opus 5.5 (Reasoning)?

GPT-5.6 Terra (Reasoning) scores 49.4 on the Intelligence Score versus 60.5 for Claude Opus 5.5 (Reasoning), the current #1. Input pricing is $2 vs $4 per 1M tokens.

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