OpenAI launched GPT-6 Astra on September 3, two days after Anthropic released Claude Fable 5.1.
Both APIs list $10 per million input tokens and $50 per million output tokens. Both cap output at 128,000 tokens. Their context windows are separated by only 50,000 tokens: 1.05 million for Astra and one million for Fable 5.1.
Leiolai 1 has an 11-million-token context window, no response output limit, and Research API pricing that starts at $0.01 per million input tokens and $0.02 per million output tokens.
| Model | Context | Max output | API input / output per 1M tokens |
|---|---|---|---|
| GPT-6 Astra | 1.05M | 128K | $10 / $50 |
| Claude Fable 5.1 | 1M | 128K | $10 / $50 |
| Leiolai 1 | 11M | No limit | Research Fast $0.01 / $0.02 |
What is GPT-6 Astra?
OpenAI calls GPT-6 Astra its most capable model and lists complex reasoning, coding, computer use, research, and document creation among its intended uses.
Through the Responses API, Astra supports web and file search, image generation, a hosted shell, computer use, MCP, skills, and tool search.
For Astra prompts above 272,000 input tokens, OpenAI doubles the input rate and charges 1.5 times the output rate for the entire request.
Astra is reaching enterprises in OpenAI’s Trusted Access Program first. API and Plus, Pro, Business, and Enterprise access are due over the following days.
What is Claude Fable 5.1?
Anthropic released Claude Fable 5.1 for demanding reasoning and long-horizon work across coding, research, documents, spreadsheets, and slides.
Fable 5.1 keeps Fable 5’s $10/$50 token price, but Anthropic cut cache reads to $0.25 per million tokens. Anthropic estimates that change lowers the cost of typical workloads by about 25 percent and highly agentic workloads by as much as 45 percent.
Fable 5.1 is available through Claude subscriptions, the Claude API, and Amazon Web Services, Google Cloud, and Microsoft Foundry.
What is Leiolai 1?
Leiolai is an intelligence that runs on consumer hardware and pays users for the compute they provide.
Leiolai 1 has an 11-million-token context window and no response output limit. Research API pricing starts at $0.01 per million input tokens and $0.02 per million output tokens.
Leiolai 1 is available in the Leiolai app and through the Leiolai API.
Which model is the better fit?
- GPT-6 Astra for work built around OpenAI’s newest coding, computer-use, research tools, and especially hands-free building.
- Claude Fable 5.1 for long-running coding, research, and knowledge work inside Anthropic’s ecosystem.
- Leiolai 1 when very long context, continued output beyond 128K, low starting API prices, or inference on consumer hardware matters most.
GPT-6 Astra and Fable 5.1 run in the cloud. Leiolai 1 runs inference across iPhones, iPads, MacBooks, Androids, and PCs.
Sources OpenAI’s GPT-6 Astra model page, OpenAI’s Astra guide, Anthropic’s Fable 5.1 announcement, Anthropic’s Fable 5.1 documentation, and Leiolai 1 launch details.