GPT-5.6 Terra
FrontierVisionToolsOpenAI · Released July 2026 · Knowledge cutoff February 2026
GPT-5.6 Terra is a balanced model in OpenAI's GPT-5.6 series, positioned between the flagship Sol tier and the cost-efficient Luna tier. It is suited for everyday coding, reasoning, and agentic...
It is part of OpenAI's GPT family, where Sol, Luna and Terra mark the current generation's capability tiers and Pro servings trade speed for deeper computation.
Facts and pricing
- Provider
- OpenAI
- Context window
- 1.1M tokens
- Input price
- 27.5 credits / 1M tokens ($2.50 raw)
- Output price
- 165 credits / 1M tokens ($15.00 raw)
- Vision (image input)
- Yes
- Tool calling
- Yes
- Extended reasoning
- No
Credits are what Zeplik bills: 1 credit = $0.10, computed from the raw provider rate with a 1.10x margin. Raw prices shown per 1M tokens.
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What GPT-5.6 Terra is best for
- Hard problems where answer quality matters more than cost: strategy, analysis, difficult writing
- Very long documents and codebases: a 1.1M-token window fits entire books or repositories in one conversation
- Working with images: screenshots, charts, photos and scanned documents alongside text
- Tool use and agents: reliably calls functions, so it can search, run skills and drive workflows
Example prompts
Prompts that suit a frontier model like GPT-5.6 Terra:
- Review this business plan and give me the three hardest questions an investor would ask
- Rewrite this announcement so it lands with both engineers and executives
- I am choosing between two job offers, help me think through the tradeoffs
- Draft a technical design doc for a rate limiter, including failure modes
OpenAI family
| Model | Context | Input cr/M | Output cr/M | Released |
|---|---|---|---|---|
| GPT-5.6 Luna Pro | 1.1M | 11.0 | 66.0 | July 2026 |
| GPT-5.6 Luna | 1.1M | 11.0 | 66.0 | July 2026 |
| GPT-5.6 Terra Pro | 1.1M | 27.5 | 165 | July 2026 |
| GPT-5.6 Terra | 1.1M | 27.5 | 165 | July 2026 |
| GPT-5.6 Sol Pro | 1.1M | 55.0 | 330 | July 2026 |
| GPT-5.6 Sol | 1.1M | 55.0 | 330 | July 2026 |
| GPT Chat Latest | 400K | 55.0 | 330 | May 2026 |
| GPT-5.5 Pro | 1.1M | 330 | 1980 | April 2026 |
| GPT-5.5 | 1.1M | 55.0 | 330 | April 2026 |
| GPT-5.4 Image 2 | 272K | 88.0 | 165 | April 2026 |
Compare GPT-5.6 Terra
Frequently asked questions
- What is GPT-5.6 Terra?
- GPT-5.6 Terra is an AI model by OpenAI. GPT-5.6 Terra is a balanced model in OpenAI's GPT-5.6 series, positioned between the flagship Sol tier and the cost-efficient Luna tier. It is suited for everyday coding, reasoning, and agentic...
- How much does GPT-5.6 Terra cost on Zeplik?
- Input tokens cost 27.5 credits per million and output tokens 165 credits per million (1 credit = $0.10; the raw provider rates are $2.50 and $15.00 per million). New accounts start with free credits.
- How long can a conversation with GPT-5.6 Terra be?
- GPT-5.6 Terra has a 1.1M-token context window (1,050,000 tokens), which covers the conversation plus any documents you attach.
- Does GPT-5.6 Terra support images and tools?
- GPT-5.6 Terra accepts image input and supports tool calling.
Related models
GPT-5.6 Luna Pro is the same underlying model as [GPT-5.6 Luna](https://openrouter.ai/openai/gpt-5.6-luna), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode
GPT-5.6 Luna is a fast, cost-efficient model in OpenAI's GPT-5.6 series. It is suited for high-volume, latency-sensitive tasks such as chat, classification, and lightweight agentic workflows, providing capable reasoning for...
GPT-5.6 Terra Pro is the same underlying model as [GPT-5.6 Terra](https://openrouter.ai/openai/gpt-5.6-terra), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode
GPT-5.6 Sol Pro is the same underlying model as [GPT-5.6 Sol](https://openrouter.ai/openai/gpt-5.6-sol), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode
GPT-5.6 Sol is the flagship model in OpenAI's GPT-5.6 series. It is suited for complex reasoning, coding, and agentic workflows, and is particularly strong at command-line and multi-step coding tasks...
GPT Chat Latest points to OpenAI's stable API alias `chat-latest` that always resolves to the latest Instant chat model used in ChatGPT. As OpenAI rolls out new Instant model updates...