GPT‑6 Astra
GPT‑6 Astra GPT-6 Astra is "rolling out today to a limited set of organizations and over the coming days will become available to all ChatGPT Plus, Pro, Business, and Enterprise users, as well as through the OpenAI API and AWS" - I've not tried it yet myself, so I don't have a great deal to…
Opening of the original on Simon Willison
Summary
OpenAI released GPT-6 Astra today, a new model for ChatGPT Plus, Pro, Business, and Enterprise users, and the OpenAI API. It competes directly with Anthropic's Fable models, matching their API pricing at $10 per million input tokens and $50 per million output tokens. Astra reportedly scores 99.9% on the ARC-AGI 3 benchmark, significantly outperforming previous models, and excels at security tasks, achieving 100% on ExploitBench.
Why it matters
This release positions OpenAI directly against Anthropic's Fable models, matching their pricing structure. Astra's reported benchmark scores, particularly on ARC-AGI 3 and ExploitBench, suggest a significant leap in capability, especially in security. The use of a custom 'Provider Adapter harness' for benchmark testing highlights a potential difference in how performance is measured and achieved, especially for complex reasoning tasks. Users should monitor how these benchmark differences translate to real-world performance and compare Astra's security capabilities against other frontier models.
Related: Google: Introducing Gemini 3.8 Flash and 3.8 Flash Cyber · Anthropic: GPT‑6 Astra · Microsoft: Meet MAI-Transcribe-2: A faster and more accurate speech recognition model · Meta: Meta Muse Code & Muse Spark Course – Build AI Agents, APIs, and Full-Stack Apps · xAI: Sam Altman "AGI by December"
Rated high: a launch, deal or policy change that changes what you can do or what it costs.
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- Claude Fable 5.1 made me a really nice animated pelicanSimon Willison · Web · Sep 1, 2026
- Introducing GPT-6 Astra: the most intelligent and aligned model in the world.OpenAI on YouTube
- Fable 5.1 just smoked ASTRA...Wes Roth
- OpenAI’s next big AI model has ‘entered the AGI era’The Verge AI
- Safety overview: GPT-6 AstraOpenAI News
- GPT-6 Astra Just Went CRITICAL...Wes Roth
- Claude Fable 5.1 made me a really nice animated pelicanSimon Willison
Questions people ask
- What is GPT-6 Astra?
- GPT-6 Astra is a new AI model from OpenAI, rolling out to ChatGPT users and the OpenAI API. It aims to compete with models like Anthropic's Fable.
- How much does GPT-6 Astra cost?
- Astra is priced at $10 per million input tokens and $50 per million output tokens, matching the rates of Claude Fable 5 and 5.1.
- How does Astra perform on benchmarks?
- Astra reportedly scores 99.9% on the ARC-AGI 3 benchmark and 100% on ExploitBench, showing strong performance, especially in security tasks.
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Page generated Sep 3, 2026. Summaries are Subvolts' own; the story belongs to Simon Willison.