GPT-5.6 Terra

GPT-5.6 Terra is OpenAI’s balanced GPT-5.6 API model for teams that want strong GPT-5.6 capability at a lower official token price than the Sol tier.

What this model is

OpenAI’s model page describes GPT-5.6 Terra as a GPT-5.6 model designed for workloads that balance intelligence and cost. It roughly corresponds to the mini model tier used in earlier GPT-5 families.

The model supports text and image input with text output. OpenAI’s GPT-5.6 guidance positions Terra as the lower-price strong-performance option between flagship Sol and high-volume Luna.

Pricing notes

The calculator on this page uses OpenAI’s official standard short-context pricing row for gpt-5.6-terra: $2.50 per 1M input tokens and $15.00 per 1M output tokens.

OpenAI’s pricing page also lists cached input at $0.25 per 1M tokens and cache writes at $3.125 per 1M tokens for the standard short-context row. The model page says prompts with more than 272K input tokens are priced at 2x input and 1.5x output for the full request. Those cached, cache-write, and long-context figures are noted here but are not used in the top-level calculator fields.

Benchmarks and specs

OpenAI’s model page lists GPT-5.6 Terra with a 1,050,000-token context window, a 128,000-token maximum output, and a Feb 16, 2026 knowledge cutoff. It also lists reasoning token support.

No benchmark score is shown until an exact benchmark source and model identity are matched to GPT-5.6 Terra.

Best fit

GPT-5.6 Terra is best for production assistants, coding workflows, research helpers, document analysis, and agent steps where GPT-5.6 quality is useful but Sol-level pricing is not needed for every request.

Use Sol for the hardest quality-first tasks, and use Luna when the priority is very high volume at the lowest GPT-5.6 tier price.

Sources

• OpenAI GPT-5.6 Terra model page
• OpenAI API pricing
• OpenAI GPT-5.6 model guidance