Overview
GPT-5.6 Terra is the balanced mid-tier model in OpenAI's GPT-5.6 series, announced on June 26, 2026 alongside the flagship Sol and the smaller Luna. OpenAI positions Terra as a production workhorse aimed at everyday business tasks such as customer support, document analysis, and high-volume application work.
Terra accepts text and image input and delivers reasoning-model capabilities at roughly half the price of Sol, with OpenAI describing it as competitive with GPT-5.5 while being 2x cheaper. In the GPT-5.6 naming system, the number identifies the generation and the tier names — Sol, Terra, Luna — identify durable capability tiers that can advance on their own cadence.
Access at launch is restricted: in coordination with the U.S. government, OpenAI began with a limited preview to around 20 vetted partner organizations through the API and Codex, with general availability across ChatGPT, Codex, and the API planned in the following weeks.
| Released | 2026-06-26 |
|---|---|
| License | Proprietary |
| Weights | API only |
| Modalities | Text, Vision |
| Status | Preview |
Benchmarks
- Terminal-Bench 2.184.3%
Scores on a 0–100 scale (25-point gridlines); higher is better. Each benchmark links to its published source.
Pricing
| Input | $2.50 / 1M tokens |
|---|---|
| Output | $15.00 / 1M tokens |
Strengths
- GPT-5.5-level quality at roughly half the input and output cost
- Reasoning-model architecture with text and image input
- Ships with the GPT-5.6 series safety stack for production deployments
- Positioned as a balanced workhorse for high-volume, everyday business tasks
Best for
- Reach for it for high-volume customer support, document analysis, and back-office workflows.
- Reach for it when you want GPT-5.5-level answers at half the per-token cost.
- Reach for it for production applications where cost per query matters more than the extra reasoning headroom of Sol.
How to access
| Provider | Model ID |
|---|---|
| OpenAI API ↗ | — |
GPT (Flagship / Thinking) — every version
The full lineage of the GPT (Flagship / Thinking) line, newest first. Every version has its own page — click any to compare specs, benchmarks and pricing.
| Version | Released | Context | License |
|---|---|---|---|
| GPT-5.6 Sol | 2026-06-26 | — | Proprietary |
| GPT-5.6 Terra | 2026-06-26 | — | Proprietary |
| GPT-5.6 Luna | 2026-06-26 | — | Proprietary |
| GPT-5.5current | 2026-04-23 | 1.05M | Proprietary |
| GPT-5.4 | 2026-03-05 | — | Proprietary |
| GPT-5.2 | 2025-12-11 | — | Proprietary |
| GPT-5.1 | 2025-11-12 | — | Proprietary |
| GPT-5 | 2025-08-07 | — | Proprietary |
| GPT-4o | 2024-05-13 | — | Proprietary |
FAQ
When was GPT-5.6 Terra released?
OpenAI announced GPT-5.6 Terra on June 26, 2026 as a limited preview, alongside GPT-5.6 Sol and GPT-5.6 Luna. Initial access was restricted to roughly 20 vetted partner organizations via the API and Codex, with broader rollout planned in the following weeks.
How much does GPT-5.6 Terra cost?
GPT-5.6 Terra is priced at $2.50 per 1M input tokens and $15.00 per 1M output tokens — roughly half the per-token cost of GPT-5.6 Sol and about 2x cheaper than GPT-5.5 while offering competitive quality.
How does GPT-5.6 Terra compare to Sol and Luna?
On Terminal-Bench 2.1, OpenAI reports Terra at 84.3%, versus 88.8% for Sol (91.9% in ultra mode) and 82.5% for Luna. Terra sits between Sol and Luna on both capability and price, and is positioned as the balanced everyday-work tier of the GPT-5.6 series.
What is GPT-5.6 Terra best for?
OpenAI positions Terra as a balanced production workhorse for everyday business tasks such as customer support, document analysis, content generation, summarization, and conversational agents where GPT-5.5-level quality at half the cost is the right tradeoff.