GPT-6

0:04 GPT-6 is OpenAI's current generation of models, released in steps between Sep 3 and Oct 26, 2026: GPT-6 Astra, the flagship, came first; GPT-6 Sol and GPT-6 Luna on Sep 22; GPT-6.1 Sol on Sep 29; and GPT-6.1 Terra on Oct 26, 2026. In ChatGPT, "GPT-6" is also the name of the default model in the Chat tab, which rolled out to every plan from Oct 7, 2026: GPT-6 Sol on paid plans, GPT-6 Luna on Free and Go. There is no single model called plain "GPT-6" in the API.

Quick facts

The GPT-6 models

1:32 OpenAI replaced the single-model naming of earlier generations with named sizes, a pattern it started with GPT-5.6 Sol, Terra and Luna in July 2026. Each GPT-6 model has its own page:

Sources: API changelog, models and pricing, OpenAI, read Nov 6, 2026. Standard tier, prompts up to 272K tokens.

GPT-6 Pro is not a separate API model: in ChatGPT it is the Pro reasoning option, "powered by GPT-6 Astra", on Pro $100, Pro $200, Business and Enterprise. On Oct 16, 2026 OpenAI said GPT-6 Pro in the chat tab gained faster replies, better tool use and "Multiple agents that can work on different parts of a task in parallel". Two specialized versions of Astra exist for vetted organizations, GPT-6-Cyber and GPT-6 Rosalind; see GPT-Rosalind and Cyber Models.

How GPT-6 rolled out

1:00 The rollout went from the most capable model to the cheapest, and from the API and the agent tabs to everyday chat:

1. Sep 3, 2026: GPT-6 Astra. OpenAI rolled it out "to a limited set of organizations" first (CNBC reported that companies in OpenAI's Daybreak cybersecurity program went first), then over the following days to Plus, Pro, Business and Enterprise, the API, Microsoft Azure and AWS Bedrock.
2. Sep 22, 2026: GPT-6 Sol and GPT-6 Luna in ChatGPT Work and Codex for Plus, Pro, Business, Enterprise and Edu, and in the API, at about half the token price of their GPT-5.6 predecessors (OpenAI API pricing). Free and Go could try Luna in the desktop app. "These models are not yet available in Chat."
3. Sep 29, 2026 (DevDay): GPT-6.1 Sol in Work, Codex and the API (Unite.AI, Sep 29, 2026).
4. Oct 7, 2026: "GPT-6 and Intelligent UI for everyone": the Chat tab switched to GPT-6 for paid plans that day and Free and Go from the next day.
5. Oct 26, 2026: GPT-6.1 Terra in Work, Codex and the API (Model Release Notes).

Secondary reports say a GPT-6.1 Astra was held back over alignment findings; no OpenAI page read on Nov 6, 2026 says so, so treat it as unconfirmed.

What changed from GPT-5?

Lower prices per token. GPT-6 Sol and Luna cost half of GPT-5.6 Sol and Luna ($2 against $4 input, $0.10 against $0.20), and GPT-6.1 Terra is half of GPT-5.6 Terra (OpenAI API pricing). Astra itself costs more per token than any GPT-5.6 model, but OpenAI's migration guide claims its estimated cost per finished task is lower than earlier models.

A million-token context. Every GPT-6 flagship accepts 1,050,000 tokens of context and 128,000 of output in the API, with prices doubling past 272K input tokens.

0:35 Intelligent UI in ChatGPT. GPT-6 answers in the Chat tab can mix text with visuals and interactive pieces, "such as calculators, bill splitters, and games", and can start answering while it is still thinking or using tools. See Intelligent UI.

2:10 New API controls. GPT-6 brought async tool calling (a tool's result can arrive later, by call_id), steering a reply mid-turn over WebSocket, changing reasoning effort mid-conversation without losing the cache, and Fast and Ultrafast speed modes (OpenAI API docs). Tool calls on Astra, Sol and Terra need the Responses API.

A higher safety rating. OpenAI calls Astra "our first model to reach the Critical level of cybersecurity capability" under its Preparedness Framework, and rated it High, not Critical, for biological and chemical risk.

How good is GPT-6?

OpenAI's own claims are strong; independent leaderboards place GPT-6 below the best Google and Anthropic models overall.

• OpenAI's numbers (Sep 3, 2026): GPT-6 Astra scores 97.6% on FrontierMath Tier 4, 99.9% on ARC-AGI-3, 57.9% on Terminal-Bench 4.0 and 72.6% on OSWorld 2.0 (offline set), ahead of GPT-5.6 Sol on each. In the same table, Claude Fable 5.1 led Humanity's Last Exam with tools (65.0% against Astra's 57.2%).
• Artificial Analysis Intelligence Index (v5, read Nov 6, 2026): Gemini 4 Carbon (high) 60, Claude Opus 5.5 (max) 59, GPT-6 Astra (max) 57, GPT-6.1 Sol (max) 55, GPT-6.1 Terra (max) 51, GPT-6 Luna (max) 28.
• LMArena Text (updated Oct 27, 2026): the best OpenAI model is GPT-5.6 Sol at 22nd; GPT-6.1 Sol is 27th and GPT-6 Astra 37th, with Gemini and Claude models at the top.
• LMArena WebDev (Oct 27, 2026): GPT-6 Astra is 2nd (1773) behind Claude Opus 5.5 (1810).

Full tables, and how to read them, are on OpenAI Benchmarks.

Where can you use GPT-6?

• ChatGPT Chat tab: GPT-6 on every plan; GPT-6 Pro (Astra) on Pro $100, Pro $200, Business and Enterprise (OpenAI Help Center). See ChatGPT Models.
• ChatGPT Work and Codex: Astra, 6.1 Sol, 6.1 Terra, 6 Sol and 6 Luna, by plan.
• OpenAI API: all five as gpt-6-astra, gpt-6-sol, gpt-6.1-sol, gpt-6.1-terra and gpt-6-luna (OpenAI API pricing).
• Clouds: OpenAI named Microsoft Azure and AWS Bedrock for Astra.

Frequently asked questions

When was GPT-6 released? OpenAI released the first GPT-6 model, GPT-6 Astra, on Sep 3, 2026. GPT-6 became the default in ChatGPT's Chat tab on Oct 7, 2026 for paid plans and from Oct 8 for Free and Go.

Is GPT-6 free in ChatGPT? Yes, in a smaller form. Free and Go users chat with a Luna model; OpenAI's release note and pricing page call it GPT-6 Luna, while its help articles say GPT-5.6 Luna. GPT-6 Sol needs Plus or higher, and GPT-6 Pro needs Pro, Business or Enterprise.

What is the difference between GPT-6 Astra, Sol and Luna? Astra is OpenAI's most capable and most expensive GPT-6 model, Sol (now GPT-6.1 Sol) comes close to it at a fifth of the token price, and Luna is the fastest and cheapest. GPT-6.1 Terra sits between Sol and Luna, aimed at writing, images and computer use.

Is GPT-6 better than Claude or Gemini? Not on every measure. OpenAI's own tables put GPT-6 Astra ahead on several agent and math tests, but on Artificial Analysis's index and LMArena's text board in late October 2026, Gemini 4 Carbon and Claude Opus 5.5 ranked above every GPT-6 model.

What is GPT-6 Pro? GPT-6 Pro is the Pro reasoning option in ChatGPT, powered by GPT-6 Astra and rationed weekly, on Pro $100, Pro $200, Business and Enterprise. It is not sold as a separate API model.

Sources

• Introducing GPT-6 Astra, OpenAI, Sep 3, 2026
• Introducing GPT-6 Astra for developers, OpenAI, Sep 4, 2026 (video)
• Introducing GPT-6 in ChatGPT with Intelligent UI, OpenAI, Oct 7, 2026 (video)
• Meet GPT-5.6, OpenAI, Jul 9, 2026 (video)
• GPT-6 Astra Is Finally Here (And It’s REALLY Good), Matt Wolfe, Sep 3, 2026 (video)
• Introducing GPT-6 Sol and Luna, OpenAI, Sep 22, 2026
• GPT-6 and Intelligent UI for everyone, OpenAI, Oct 7, 2026
• Introducing GPT-5.6, OpenAI, Jul 9, 2026
• GPT-6 Astra System Card, OpenAI Deployment Safety Hub, Sep 3, 2026, read Nov 6, 2026
• API changelog, OpenAI, read Nov 6, 2026
• Models, OpenAI API docs, read Nov 6, 2026
• GPT-6 Astra model page, OpenAI API docs, read Nov 6, 2026
• Pricing, OpenAI API docs, read Nov 6, 2026
• Using the latest model, OpenAI API docs, read Nov 6, 2026
• GPT-6 and other models in ChatGPT, OpenAI Help Center, read Nov 6, 2026
• ChatGPT release notes, OpenAI Help Center, read Nov 6, 2026
• Model Release Notes, OpenAI Help Center, read Nov 6, 2026
• OpenAI announces rollout of GPT-6 Astra model, CNBC, Sep 3, 2026
• OpenAI unveils GPT-6.1 Sol at DevDay, Unite.AI, Sep 29, 2026
• OpenAI launches GPT-6.1 Terra, BleepingComputer, Oct 26, 2026
• Artificial Analysis model leaderboard, read Nov 6, 2026
• LMArena Text leaderboard, updated Oct 27, 2026, read Nov 6, 2026
• LMArena WebDev leaderboard, updated Oct 27, 2026, read Nov 6, 2026