Compare models
Put models side by side on price, context, capabilities, and benchmarks.
Claude Fable 5.1 is Anthropic's most capable model, released September 2026 as an upgrade to Claude Fable 5 for coding, knowledge work, and long-running problem-solving, with a 1M-token context window. It improves agentic coding by over 30% and doubles its predecessor's Terminal-Bench-Science score while cutting costs through cheaper cache reads, and is the openly available counterpart to the more tightly safeguarded Mythos 5.1.
GPT-6 Astra is OpenAI's flagship GPT-6-generation model (1.05M-token context, up to 128K output tokens, priced at $10/$50 per million input/output tokens), built for demanding end-to-end work. It excels at advanced analysis, software engineering, deep research, scientific work, and document creation, with particular strength in long-horizon agentic tasks involving computer and browser use.
Benchmarks
Head-to-head scores across reasoning, coding, and agentic indices, plus per-domain rankings.