GPT-5.6 Sol vs. Claude Fable: Why OpenAI’s new model crushes my benchmark

Playback speed 1× Subtitles Share post Share post at current time Share from 0:00 0:00 / GPT-5.6 Sol vs. Claude Fable: Why OpenAI’s new model crushes my benchmark 🎙️GPT 5.6-Sol beats Fable on prototypes, PRDs, and browser use in my 5-category How I AI benchmark, and here's exactly where each model earns its spot. CLAIRE VO JUL 09, 2026 Transcript

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.

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What you’ll learn:

How 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

The difference between GPT-5.6 Sol (Terra) and Sol for PRD writing

How Fable’s precision and pedantry made it harder to collaborate with, and the exact moment Sol broke through where Fable got stuck

Why Sonnet 5 is still my go-to for agentic voice in OpenClaw, even after this whole benchmark

How I used GPT-5.6 Sol in Codex to build a fully gamified homework tracking app for my kids in one shot

The video editing use case that saved me hours clipping a talk I gave at Cursor’s event

How to use Codex plus GPT-5.6 and Chrome for browser automation, and why this is my single most-loved use case right now

In this episode, I cover:

(00:00) Intro

(01:10) The three GPT-5.6 models: Sol, Terra, Luna

(02:17) Pricing: Sol vs. Fable API costs

(03:24) The How I AI benchmark

(05:03) Claire-weighted Index results

(07:00) Per-task winners: prototypes, PRDs, agentic voice

(11:59) What Claire actually rewards

(13:20) Full-fidelity prototype side-by-sides (Sol vs. Fable)

(17:45) Wireframes

(18:19) Agentic voice

(19:15) Where Sol is better than other models

(23:56) Gamified kids’ homework app, built in one shot

(28:02) Fable’s pedantry problem and how Sol broke through it

(31:49) Two bonus use cases: video editing and browser use

(35:08) Final summary and model recommendations

Tools referenced:

• GPT 5.6 (Sol, Terra, Luna): https://help.openai.com/en/articles/20001325-a-preview-of-gpt-56-sol-terra-and-luna

• Codex: https://openai.com/codex

• ChatPRD: https://www.chatprd.ai/

• CapCut: https://www.capcut.com/

• Math Academy: https://www.mathacademy.com/

Other references:

• Cursor event where Claire spoke on the future of PM: https://www.youtube.com/watch?v=4CAFK-rc26A

• ChatPRD blog (where benchmark outputs will be published): https://www.chatprd.ai/

Where to find Claire Vo:

ChatPRD: https://www.chatprd.ai/

Website: https://clairevo.com/

LinkedIn: https://www.linkedin.com/in/clairevo/

X: https://x.com/clairevo

Production and marketing by https://penname.co/. For inquiries about sponsoring the podcast, email jordan@penname.co.

7 Likes Discussion about this video Comments Restacks How I AI How I AI, hosted by Claire Vo, is for anyone wondering how to actually use these magical new tools to improve the quality and efficiency of their work. In each episode, guests will share a specific, practical, and impactful way they’ve learned to use AI in their work or life. Expect 30-minute episodes, live screen sharing, and tips/tricks/workflows you can copy immediately. If you want to demystify AI and learn the skills you need to thrive in this new world, this podcast is for you. Listen on Substack App Apple Podcasts Spotify YouTube Overcast Pocket Casts RSS Feed Appears in episode Claire Vo Writes Claire’s Substack Subscribe Recent Episodes What a harness is and how to build one with Claude Agent SDK JUL 8 • CLAIRE VO How I run autonomous coding agents from my phone with OpenAI Symphony + Linear | Alessio Fanelli (Kernel Labs) JUL 6 • CLAIRE VO Sonnet 5 review: I ran 64 generations to find out if it's worth it JUN 30 • CLAIRE VO No Figma. No Jira. No docs. How Gusto built a new product line with Claude Code | Eddie Kim (CTO) JUN 29 • CLAIRE VO GLM 5.2: why I’m replacing Opus in Claude Code with this new model JUN 24 • CLAIRE VO How Claude Mythos found a 15-year-old bug in Mozilla Firefox | Brian Grinstead JUN 22 • CLAIRE VO How to design AI agent loops: schedules, goals, and subagents in Claude Code and Codex JUN 17 Ready for more?