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What is GPT-6 Astra?
GPT-6 Astra is OpenAI's most capable model, built for the hardest end-to-end work. OpenAI positions it for complex reasoning, coding, computer use, research, and document creation, with reasoning_effort support for low, medium, high, xhigh, and max.
OpenAI began releasing GPT-6 Astra on September 3, 2026, with API availability as gpt-6-astra. Compared with earlier OpenAI models such as GPT-5.6 Sol, Astra is positioned as a stronger model for complex professional work, software engineering, computer use, cybersecurity, science, and long-context workflows.
GPT-6 Astra: Key Specs
Below are GPT-6 Astra's main specs and how they translate into real-world behavior.
- 1,050,000-token context window: GPT-6 Astra can process very large prompts, long documents, codebases, and retrieval bundles, which helps reduce chunking in end-to-end workflows.
- 128,000 maximum output tokens: The model can generate long reports, structured documents, code plans, analysis, and multi-section outputs when a task requires extended responses.
- Text input and output with image input: GPT-6 Astra can combine written and visual context while returning text, supporting document review, screenshot analysis, computer-use tasks, and multimodal reasoning.
- Reasoning token support with low, medium, high, xhigh, and max reasoning_effort: Developers can allocate more reasoning effort to complex coding, research, analysis, and agentic tasks.
- $10.00 input, $1.00 cached input, $12.50 cache writes, and $50.00 output per 1M text tokens: This standard pricing applies before long-context multipliers, with prompts over 272K input tokens priced at $20.00 input, $2.00 cached input, $25.00 cache writes, and $75.00 output.
- Streaming, function calling, structured outputs, and Responses API tools: GPT-6 Astra supports web search, file search, image generation, code interpreter, hosted shell, apply patch, skills, computer use, MCP, and tool search for advanced workflows.
Compare GPT-6 Astra, GPT-5.6 Sol & GPT-5.6 Terra
A brief overview of how each model differs in power, speed, and use cases.
| Feature | GPT-6 Astra | GPT-5.6 Terra | GPT-5.6 Luna |
|---|---|---|---|
| Knowledge Cutoff | April 30, 2026 | February 16, 2026 | February 16, 2026 |
| Context Window (Tokens) | 1,050,000 tokens | 1,050,000 tokens | 1,050,000 tokens |
| Max Output Tokens | 128,000 tokens | 128,000 tokens | 128,000 tokens |
| Input Modalities | Text, image | Text, image | Text, image |
| Output Modalities | Text | Text | Text |
| Latency (OpenRouter Data) | Not officially disclosed for Standard processing; Fast mode is available and delivers up to 2x the speed of Standard processing at 2x the Standard price. | Fast; real-world latency varies by prompt length, output length, tool use, reasoning effort, and deployment conditions. | Fast; real-world latency varies by prompt length, output length, tool use, reasoning effort, and deployment conditions. |
| Speed | Standard and Fast mode available; exact speed is not officially disclosed. | Fast | Fast |
| Input / Output Cost per 1M Tokens | $10.00 input, $1.00 cached input, $12.50 cache writes, $50.00 output; prompts over 272K input tokens are priced at $20.00 input, $2.00 cached input, $25.00 cache writes, and $75.00 output. | $2.50 input, $0.25 cached input, $15.00 output | $1.00 input, $0.10 cached input, $6.00 output |
| Reasoning Performance | Highest. Official evaluations list GPT-6 Astra at 59.3% on Agents' Last Exam, 97.6% on FrontierMath Tier 4 v2, 96.0% on GPQA Diamond, 57.2% on Humanity's Last Exam with tools, and 99.9% on ARC-AGI-3. | High. Official GPT-5.6 evaluations list Terra at 50.4% on Agents' Last Exam, 55 on Artificial Analysis Intelligence Index v4.1, 57.7% on HealthBench Professional, and 87.5% on BrowseComp. | High. Official GPT-5.6 Luna evaluations include GPQA Diamond 92.3%, FrontierMath Tier 1-3 v2 78.6%, FrontierMath Tier 4 v2 58.5%, and Artificial Analysis Intelligence Index v4.1 score 51.2. |
| Coding Performance (on SWE-bench Verified) | Highest. Official evaluations list GPT-6 Astra at 57.9% on Terminal-Bench 4.0, 74.1% on DeepSWE v1.1, 64.5% on FrontierCode 1.1 Extended, 53.3% on FrontierCode 1.1 Main, and 67.0 on Artificial Analysis Coding Agent Index v1.4. | Strong. Official GPT-5.6 evaluations list Terra at 77.4 on Artificial Analysis Coding Agent Index v1.1, 63.4% on SWE-Bench Pro, 69.6% on DeepSWE v1.1, and 87.4% on Terminal-Bench 2.1. | Strong for a lower-cost model. Official evaluations include Artificial Analysis Coding Agent Index v1.1 score 74.6, SWE-Bench Pro 62.7%, DeepSWE v1.1 67.2%, and Terminal-Bench 2.1 84.7%. |
| Best For | Complex reasoning, coding, computer use, research, document creation, cybersecurity defense, science, professional work, and advanced agent workflows | Production coding, structured data extraction, content workflows, general-purpose agents, long-context analysis, and cost-aware knowledge work | High-volume classification, summarization, routing, structured extraction, real-time applications, coding support, and cost-sensitive agent workflows |
Source: OpenAI GPT-6 Astra Documentation
Best Cases to Use GPT-6 Astra
GPT-6 Astra is best for complex reasoning, coding, and end-to-end work.
- For professionals and knowledge workers: Complete complex end-to-end projects that combine in-depth analysis, research, tool use, document creation, and multistep execution.
- For developers and engineering teams: Plan software architecture, write and debug code, run tests, review changes, and handle complex tasks across large repositories.
- For researchers and scientists: Analyze extensive source material, work across long contexts, review evidence, interpret data, and support demanding scientific or technical investigations.
- For businesses and operations teams: Navigate software, organize information, complete forms, evaluate interfaces, and automate multistep workflows involving documents, spreadsheets, and business tools.
- For cybersecurity professionals: Review code securely, identify and prioritize vulnerabilities, develop patches, and support authorized defensive security analysis within applicable safeguards.
- For creators and product teams: Produce polished documents, spreadsheets, presentations, websites, apps, and games that require strong structure, visual judgment, and continuity across multiple stages.
How to Access GPT-6 Astra
Accessing GPT-6 Astra is straightforward, whether you want a convenient chat experience or direct API integration for advanced workflows.
1. Official API
OpenAI lists GPT-6 Astra as gpt-6-astra in the API. It supports Chat Completions, Responses, and Batch endpoints, text and image input, text output, streaming, function calling, structured outputs, and supported Responses API tools.
2. EssayDone AI Chat
EssayDone AI Chat provides access to GPT-6 Astra through an easy-to-use chat interface when the model is available in the product.
Use GPT-6 Astra for writing, study, in-depth research, coding support, document analysis, and productivity workflows without purchasing a ChatGPT subscription or signing in with an OpenAI account.
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FAQ
Here are some frequently asked questions about GPT-6 Astra.
Yes. GPT-6 Astra supports reasoning tokens and reasoning_effort settings of low, medium, high, xhigh, and max. OpenAI positions it for complex reasoning, coding, computer use, research, and document creation.
OpenAI lists GPT-6 Astra Standard API pricing at $10.00 per 1M input tokens, $1.00 per 1M cached input tokens, $12.50 per 1M cache-write tokens, and $50.00 per 1M output tokens. Prompts over 272K input tokens are priced at 2x input and cache rates and 1.5x output for the full request, which equals $20.00 input, $2.00 cached input, $25.00 cache writes, and $75.00 output per 1M tokens. Batch and Flex are 50% of Standard rates, and Fast mode is 2x the applicable rates.
GPT-6 Astra is optimized for hard end-to-end work, including complex reasoning, coding, computer use, research, document creation, professional workflows, scientific analysis, and authorized defensive cybersecurity tasks.
GPT-6 Astra supports text input and output plus image input. It can use visual context for document review, screenshots, computer-use tasks, and multimodal analysis, but audio and video are not supported modalities for this model.
Compared with GPT-5.6 Sol, GPT-6 Astra is OpenAI's newer and more capable model for hard end-to-end work, with official improvements across computer use, coding, professional tasks, long context, cybersecurity, science, and alignment evaluations. Compared with GPT-5.6 Terra, GPT-6 Astra is positioned for higher-capability complex work, while Terra is a lower-cost balanced GPT-5.6 option for everyday production workloads.
Using GPT-6 Astra in EssayDone AI Chat can provide a convenient way to access OpenAI's most capable model for writing, research, study, coding support, document analysis, and productivity tasks without setting up the API.