Overview
Analysis
Claude Fable 5.2 vs Gemini 3.1 Pro Preview Custom Tools vs GPT-6 Astra: side-by-side summary
Claude Fable 5.2, Gemini 3.1 Pro Preview Custom Tools, and GPT-6 Astra are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
Claude Fable 5.2, from Anthropic, has a 1,000,000-token context window and is priced at $8/M tokens input, $40/M tokens output on OpenRouter.
Gemini 3.1 Pro Preview Custom Tools, from Google, has a 1,048,576-token context window and is priced at $2/M tokens input, $12/M tokens output on OpenRouter.
GPT-6 Astra, from OpenAI, has a 1,050,000-token context window and is priced at $10/M tokens input, $50/M tokens output on OpenRouter.
| Attribute | Claude Fable 5.2 | Gemini 3.1 Pro Preview Custom Tools | GPT-6 Astra |
|---|---|---|---|
| Context window | 1,000,000 tokens | 1,048,576 tokens | 1,050,000 tokens |
| Price | $8/M tokens input, $40/M tokens output | $2/M tokens input, $12/M tokens output | $10/M tokens input, $50/M tokens output |
| Provided by | Anthropic | OpenAI | |
| Model page | Claude Fable 5.2 model details, providers and pricing | Gemini 3.1 Pro Preview Custom Tools model details, providers and pricing | GPT-6 Astra model details, providers and pricing |