GPT-6.1 Terra — Specifications
Compiled by Mustafa Ihsan from the vendor’s published documentation · Last updated
| Developer | OpenAI |
|---|---|
| Type | Reasoning / agentic |
| Modality | Text, vision |
| Parameters | Undisclosed |
| Context window | 1.05M |
| Max output | 128K |
| License | Proprietary |
| Open weights | No |
| Released | 2026-10 |
| Input price | $1.00 /1M |
| Output price | $5.00 /1M |
| API providers | OpenAI API, Microsoft Azure, AWS Bedrock |
Benchmarks
| OpenAI-reported | Terminal-Bench 4.0 50.3% at max reasoning effort (GPT-5.6 Terra: 21.5%). |
|---|
What is GPT-6.1 Terra?
GPT-6.1 Terra is OpenAI’s fast, efficient model for visual reasoning, precise computer use and clear, natural writing, released on 26 October 2026 and listed among the four flagship models on OpenAI’s API. According to OpenAI, it is a significant step up from GPT-5.6 Terra, and its standard API prices are 50% lower than those of GPT-5.6 Terra and GPT-6.1 Sol. The model page lists a 1,050,000-token context window, up to 922,000 input tokens, up to 128,000 output tokens, text and image input, a 1 June 2026 knowledge cutoff and reasoning effort from none to max (default medium).
Standard pricing is $1 per million input tokens, $0.05 for cached input and $5 per million output tokens. Prompts above 272K input tokens are billed for the full request at $2, $0.10 and $7.50. Batch and Flex cost half the Standard rates ($0.50 / $0.025 / $2.50, or $1 input and $3.75 output at long context), Fast mode costs double, and regional processing adds 10% where available (see OpenAI’s pricing page).
OpenAI made it available to Plus, Pro, Enterprise and Edu users in ChatGPT Work and Codex; its release notes say it is not offered in Chat. Developers call it as gpt-6.1-terra in the OpenAI API, and Amazon Bedrock and Microsoft Foundry list it; Google Cloud access is a private preview that has to be requested. OpenAI says GPT-6.1 Sol ($2 / $10) and GPT-6 Astra remain the better choice for the most complex coding, while GPT-6 Luna is its most efficient model for high-volume tasks. Estimate a monthly bill with the AI API cost calculator.
GPT-6.1 Terra pricing: API cost per 1M tokens
| Input (per 1M tokens) | $1.00 |
|---|---|
| Output (per 1M tokens) | $5.00 |
| Output/input ratio | 5× |
| Blended (4:1 in:out) | $1.80 per 1M tokens |
What GPT-6.1 Terra costs per month
Real monthly spend at a 4:1 input-to-output mix — the ratio a typical chat or RAG workload actually produces.
| Workload | Tokens / month | Cost / month |
|---|---|---|
| Side project | 1M in / 0.25M out | $2.25 |
| Small team | 20M in / 5M out | $45 |
| Production | 200M in / 50M out | $450 |
Run your own numbers in the AI API cost calculator.
Cheaper alternatives to GPT-6.1 Terra
| Model | Blended $/1M | You save |
|---|---|---|
| Llama 3.1 8B open | $0.0240 | 99% cheaper |
| Mistral NeMo 12B open | $0.0292 | 98% cheaper |
| Gemma 3 4B open | $0.0600 | 97% cheaper |
Frequently asked questions
How much does GPT-6.1 Terra cost per 1M tokens?
GPT-6.1 Terra costs $1.00 per 1M input tokens and $5.00 per 1M output tokens. At a typical 4:1 input-to-output mix that blends to about $1.80 per 1M tokens.
How much does GPT-6.1 Terra cost per month?
A small-team workload of 20M input and 5M output tokens a month costs about $45 on GPT-6.1 Terra. A side project (1M in / 0.25M out) costs roughly $2.25.
What is a cheaper alternative to GPT-6.1 Terra?
Llama 3.1 8B is the strongest cheaper option in our database at $0.0240 per 1M blended — about 99% less than GPT-6.1 Terra. It is also open-weight, so self-hosting is an option.
Can I run GPT-6.1 Terra locally?
No. GPT-6.1 Terra is a closed, API-only model — the weights are not released, so it cannot be self-hosted.
Why does GPT-6.1 Terra charge more for output than input?
Output tokens are generated one at a time and cannot be batched the way a prompt can, so they cost the provider more to serve. GPT-6.1 Terra charges 5× more for output, which is why prompt-heavy workloads are far cheaper to run than generation-heavy ones.
Prices are the published list rates for the model's primary API and are reviewed as providers change them. Volume, batch and cached-input discounts are not included. Compare every model side by side in the AI models database or the LLM leaderboard.