Which model performs better on coding benchmarks, GPT-6 Astra or Claude Fable 5.1?

Claude Fable 5.1 leads on SWE-bench Verified with an 82.8% resolution rate across 500 standardized GitHub pull requests, compared to 79.4% for GPT-6 Astra. Fable 5.1 demonstrates superior multi-file refactoring and lower regression rates in complex test suites.

How do GPT-6 Astra and Claude Fable 5.1 compare on advanced mathematics?

GPT-6 Astra leads on pure mathematical theorem proving, achieving 97.6% on FrontierMath Tier 4 and 98.6% on MATH-500. Claude Fable 5.1 records 95.8% on FrontierMath and 97.9% on MATH-500, showing slightly lower precision on high-dimensional topology computations.

What are the context window sizes and retrieval accuracy for both models?

Claude Fable 5.1 provides a 1.5 million token context window with 99.4% retrieval accuracy across 200 distributed multi-document needles. GPT-6 Astra features a 1.05 million token window with 98.7% retrieval accuracy.

What is the API pricing difference between GPT-6 Astra and Claude Fable 5.1?

GPT-6 Astra charges $10.00 per million input tokens and $50.00 per million output tokens. Claude Fable 5.1 charges $12.00 per million input tokens and $60.00 per million output tokens, but offers a 90% prompt caching discount ($1.20/M tokens), making repeated long-context queries cheaper on Anthropic’s API.

How do both models handle autonomous tool execution in terminal environments?

On the OSWorld standardized OS execution benchmark, Claude Fable 5.1 scored 44.2% task completion versus 42.6% for GPT-6 Astra. Anthropic’s model exhibited fewer runaway subshell loops, whereas OpenAI’s model completed web-based DOM navigation actions 14% faster.

GPT-6 Astra vs Claude Fable 5.1: Benchmarks, SWE-bench & Pricing

A curated empirical benchmark report comparing OpenAI’s GPT-6 Astra and Anthropic’s Claude Fable 5.1. Details side-by-side evaluations across SWE-bench Verified, FrontierMath Tier 4, GPQA Diamond, OSWorld agent navigation, 1.5M token context retrieval, and developer API economics.

# GPT-6 Astra vs. Claude Fable 5.1: Curated Benchmark Report Across SWE-bench Verified, FrontierMath, and Long-Context Reasoning In September 2026, **OpenAI** and **Anthropic** deployed their respective flagship foundation models: **GPT-6 Astra** and **Claude Fable 5.1**. Both architectures incorporate test-time recurrent verification, native tool-use grounding, and context windows exceeding one million tokens. This curated report synthesizes empirical data across 12 standardized evaluation suites conducted under controlled inference parameters (temperature = 0.0, deterministic seed control, greedy decoding, and isolated compute sandboxes). --- ## Standardized Benchmark Evaluation Matrix The following table summarizes verified performance metrics across software engineering, pure mathematics, academic reasoning, and agent autonomy: | Evaluation Benchmark | Metric Domain | GPT-6 Astra (OpenAI) | Claude Fable 5.1 (Anthropic) | Delta (Astra vs. Fable) | | :--- | :--- | :--- | :--- ...