Model comparison

Claude Fable 5.1 vs GPT-6 Astra

Compare pricing, context windows and capabilities from OpenRouter. Open either model’s page to check availability and try it online.

anthropicClaude Fable 5.1newanthropic/claude-fable-5.1openaiGPT-6 Astranewopenai/gpt-6-astra

Measured intelligence and task cost

Two current intelligence leaders from different providers. Artificial Analysis index v4.3, updated 2026-09-21.

Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback): 53.4 intelligence · $7.63 / AA task

GPT-6 Astra (max): 52.7 intelligence · $3.26 / AA task

Highest reasoning effort with both measurements available. Benchmark task costs are not OpenCraft task quotes; your settings and workload can differ.

Input price /M$10.00$5.002× cheaper

Output price /M$50.00$25.002× cheaper

Cache read /M$0.252× cheaper$0.50

Context window1M1.1M

Catalog date1 Sept 20264 Sept 2026

What the same turn costs

Estimates from published token rates — stated token counts, not measurements.

Quick answer2K tokens in, 600 outClaude Fable 5.1$0.05GPT-6 Astra$0.0252× cheaper

10-slide deck build60K tokens in, 9K outClaude Fable 5.1$1.05GPT-6 Astra$0.5252× cheaper

150-page PDF read200K tokens in, 4K outClaude Fable 5.1$2.20GPT-6 Astra$1.102× cheaper

Capabilities

Bothtool-usevisionreasoning

Claude Fable 5.1: text, image, file → text · GPT-6 Astra: file, image, text → text

Which model should you use?

Start with the token cost for your workload, the context you need, and supported input types. A lower price or larger context window does not establish better answer quality.

To compare answers, open each model in a separate chat and use the same prompt. Token tables use published specs and estimates; any measured AA results above are a separate benchmark.

Try Claude Fable 5.1 — pricing and availability Try GPT-6 Astra — pricing and availability