Claude Fable 5 vs GPT-5.6 Sol

Side-by-side comparison. Updated 2026-08-23.

Summary

Compare Claude Fable 5 and GPT-5.6 Sol across pricing, context window, modalities, strengths, weaknesses, and best-fit workloads.

Use the details below to weigh cost, context, modalities, and workload fit.

Claude Fable 5
by Anthropic
Input pricing
$10.00 /1M input tokens
Full review →
GPT-5.6 Sol
by OpenAI
Input pricing
$5.00 /1M input tokens
Full review →

At a Glance

Side-by-side comparison of Claude Fable 5 and GPT-5.6 Sol
Attribute Claude Fable 5 GPT-5.6 Sol
Lab Anthropic OpenAI
Tags Agentic Coding Intelligent Reasoning Long Context Agentic Coding Intelligent Long Context Reasoning
Context 1,000,000 tokens 1,050,000 tokens
Input price $10.00/1M $5.00/1M
Output price $50.00/1M $30.00/1M
Input modalities Image, Text Text
Output modalities Text Text

Claude Fable 5 Strengths

  • #1 Intelligence Index at 64.9
  • 1M-token context window
  • 95% on SWE-bench Verified
  • Strong agentic and coding performance
  • Vision and scientific research capable

GPT-5.6 Sol Strengths

  • Terminal-Bench 2.1 SOTA (91.9% in Ultra mode)
  • Ultra multi-agent mode coordinates parallel sub-agents for complex tasks
  • 1.05M-token context for long-horizon agentic work
  • Max reasoning-effort control for deeper single-pass reasoning
  • New predictable prompt-caching with explicit cache controls

Claude Fable 5 vs GPT-5.6 Sol

GPT-5.6 Sol and Claude Fable 5 are both aimed at long-horizon, agentic work, but they emphasize different trade-offs. Sol is the cheaper option on the current list prices and offers a slightly larger 1.05M-token context window, plus explicit max-reasoning and multi-agent controls. Fable 5 costs more, but its current profile leads on the Intelligence Index and SWE-bench Verified, with strong autonomous software-engineering and research positioning. Choose Sol when controllable reasoning, coordinated sub-agents, and lower token cost matter most; choose Fable 5 when frontier coding and complex knowledge-work performance justify the premium.