{"slug": "gpt-5-6-sol-vs-claude-fable-why-openais-new-model-crushes-my-benchmark", "title": "GPT-5.6 Sol vs. Claude Fable: Why OpenAI’s new model crushes my benchmark", "summary": "OpenAI's GPT-5.6 Sol outperformed GPT-5.6 Terra, Luna, Claude Fable 5, and Sonnet 5 on Claire Vo's custom benchmark across PRDs, prototypes, wireframes, debugging, and agentic voice tasks. Sol also demonstrated practical advantages in building a gamified homework tracking app in one shot and automating browser tasks, while Sonnet 5 remained preferred for agentic voice in OpenClaw.", "body_md": "GPT-5.6 Sol is back, and I ran it through my full How I AI vibe benchmark against GPT-5.6 Terra, Luna, Claude Fable 5, and Sonnet 5 across five categories: PRDs, prototypes, wireframes, debugging, and agentic voice. Sol won by a meaningful margin on my Claire Weighted Index (70% my taste, 30% Terminal Bench 2.1), and I also tested two use cases I can't stop thinking about: building a gamified homework tracking app for my kids in one shot with Codex, and browser automation with Chrome that burned through 500 LinkedIn replies while I did literally nothing.\n\n**Listen or watch on YouTube, Spotify, or Apple Podcasts**\n\n### What you’ll learn:\n\nHow I scored five AI models (including GPT 5.6 Sol, Fable 5, and Sonnet 5) using my “Claire Weighted Index” benchmark across PRDs, prototypes, code, and agentic voice\n\nThe difference between GPT-5.6 Sol (Terra) and Sol for PRD writing\n\nHow Fable’s precision and pedantry made it harder to collaborate with, and the exact moment Sol broke through where Fable got stuck\n\nWhy Sonnet 5 is still my go-to for agentic voice in OpenClaw, even after this whole benchmark\n\nHow I used GPT-5.6 Sol in Codex to build a fully gamified homework tracking app for my kids in one shot\n\nThe video editing use case that saved me hours clipping a talk I gave at Cursor’s event\n\nHow to use Codex plus GPT-5.6 and Chrome for browser automation, and why this is my single most-loved use case right now\n\n### In this episode, I cover:\n\n([00:00](https://www.youtube.com/watch?v=gAWbvEwUoiI)) Intro\n\n([01:10](https://www.youtube.com/watch?v=gAWbvEwUoiI&t=70s)) The three GPT-5.6 models: Sol, Terra, Luna\n\n([02:17](https://www.youtube.com/watch?v=gAWbvEwUoiI&t=137s)) Pricing: Sol vs. Fable API costs\n\n([03:24](https://www.youtube.com/watch?v=gAWbvEwUoiI&t=204s)) The How I AI benchmark\n\n([05:03](https://www.youtube.com/watch?v=gAWbvEwUoiI&t=303s)) Claire-weighted Index results\n\n([07:00](https://www.youtube.com/watch?v=gAWbvEwUoiI&t=420s)) Per-task winners: prototypes, PRDs, agentic voice\n\n([11:59](https://www.youtube.com/watch?v=gAWbvEwUoiI&t=719s)) What Claire actually rewards\n\n([13:20](https://www.youtube.com/watch?v=gAWbvEwUoiI&t=800s)) Full-fidelity prototype side-by-sides (Sol vs. Fable)\n\n([17:45](https://www.youtube.com/watch?v=gAWbvEwUoiI&t=1065s)) Wireframes\n\n([18:19](https://www.youtube.com/watch?v=gAWbvEwUoiI&t=1099s)) Agentic voice\n\n([19:15](https://www.youtube.com/watch?v=gAWbvEwUoiI&t=1155s)) Where Sol is better than other models\n\n([23:56](https://www.youtube.com/watch?v=gAWbvEwUoiI&t=1436s)) Gamified kids’ homework app, built in one shot\n\n([28:02](https://www.youtube.com/watch?v=gAWbvEwUoiI&t=1682s)) Fable’s pedantry problem and how Sol broke through it\n\n([31:49](https://www.youtube.com/watch?v=gAWbvEwUoiI&t=1909s)) Two bonus use cases: video editing and browser use\n\n([35:08](https://www.youtube.com/watch?v=gAWbvEwUoiI&t=2108s)) Final summary and model recommendations\n\n### Tools referenced:\n\n• GPT 5.6 (Sol, Terra, Luna): [https://help.openai.com/en/articles/20001325-a-preview-of-gpt-56-sol-terra-and-luna](https://help.openai.com/en/articles/20001325-a-preview-of-gpt-56-sol-terra-and-luna)\n\n• Codex: [https://openai.com/codex](https://openai.com/codex)\n\n• ChatPRD: [https://www.chatprd.ai/](https://www.chatprd.ai/)\n\n• CapCut: [https://www.capcut.com/](https://www.capcut.com/)\n\n• Math Academy: [https://www.mathacademy.com/](https://www.mathacademy.com/)\n\n### Other references:\n\n• Cursor event where Claire spoke on the future of PM: [https://www.youtube.com/watch?v=4CAFK-rc26A](https://www.youtube.com/watch?v=4CAFK-rc26A)\n\n• ChatPRD blog (where benchmark outputs will be published): [https://www.chatprd.ai/](https://www.chatprd.ai/)\n\n### Where to find Claire Vo:\n\nChatPRD: [https://www.chatprd.ai/](https://www.chatprd.ai/)\n\nWebsite: [https://clairevo.com/](https://clairevo.com/)\n\nLinkedIn: [https://www.linkedin.com/in/clairevo/](https://www.linkedin.com/in/clairevo/)\n\nProduction and marketing by [https://penname.co/](https://penname.co/). For inquiries about sponsoring the podcast, email [[email protected]](/cdn-cgi/l/email-protection).", "url": "https://wpnews.pro/news/gpt-5-6-sol-vs-claude-fable-why-openais-new-model-crushes-my-benchmark", "canonical_source": "https://www.lennysnewsletter.com/p/gpt-56-sol-vs-claude-fable-why-openais", "published_at": "2026-07-09 17:33:57+00:00", "updated_at": "2026-07-09 17:49:40.693390+00:00", "lang": "en", "topics": ["artificial-intelligence", "large-language-models", "ai-products", "ai-tools"], "entities": ["OpenAI", "GPT-5.6 Sol", "Claude Fable 5", "Sonnet 5", "Codex", "Claire Vo", "ChatPRD", "OpenClaw"], "alternates": {"html": "https://wpnews.pro/news/gpt-5-6-sol-vs-claude-fable-why-openais-new-model-crushes-my-benchmark", "markdown": "https://wpnews.pro/news/gpt-5-6-sol-vs-claude-fable-why-openais-new-model-crushes-my-benchmark.md", "text": "https://wpnews.pro/news/gpt-5-6-sol-vs-claude-fable-why-openais-new-model-crushes-my-benchmark.txt", "jsonld": "https://wpnews.pro/news/gpt-5-6-sol-vs-claude-fable-why-openais-new-model-crushes-my-benchmark.jsonld"}}