Lenny’s AI Builders

devs are paying double for the old GPT on the API - GPT-5.6 Sol costs $4 in / $20 out per million tokens, GPT-6.1 Sol $2 / $10 - and swearing it's better than the new one. so i ran both on three of my real jobs (a broken test in Threadify, a video pipeline bug and my landing page copy), two runs each, with a blind judge from a different AI that only saw A and B. also this week: GPT-6 Pro running agents in parallel, Claude writing 90% of Claude Code, X paying creators to post video, Claude Code answering sooner, and moving your AI memory into Grok Bot. the practical: run your own model bake-off on your own work. give the prompt below to your agent. my recording cut out before i read it on camera, so here it is in full: I want to know which AI model is actually better for MY work - not on benchmarks. Run a blind bake-off. The job: [paste one real task from your week - a bug, a failing test, a page of copy] Model A: gpt-5.6-sol Model B: gpt-6.1-sol (swap in any two models your CLI can run) Prices per million tokens (OpenAI pricing page, 17 Oct 2026): gpt-5.6-sol $4 in / $0.40 cached / $20 out; gpt-6.1-sol $2 in / $0.10 cached / $10 out. 1. Make two clean copies of this project in a temp folder. Never touch my real folder. 2. Run the job once in each copy with the same prompt and the same effort setting: codex exec -m [model] -c model_reasoning_effort=medium --json "[the job]" Time each run and save its token usage. 3. Run my tests in both copies and note what passed. 4. Hide the model names. Label the two results A and B in a random order. Ask a different AI to judge them (for example: claude -p) - give it only the job, the two diffs and the test results, and ask for a 0-100 score and one sentence why for each. 5. Show me one table: tests passed, judge score, minutes, and cost at today's API prices. Then tell me which model to use for this kind of job - and say plainly if it's too close to call. Drafts only: don't push, merge or publish anything. chapters 0:00 devs pay double for the old GPT 0:11 my blind bake-off: 3 real jobs, 2 models 0:34 why devs went back to the 2x model 1:38 this is the LAB 1:54 stop reading benchmarks 2:13 GPT-6 Pro runs agents in parallel 4:21 Claude writes 90% of Claude Code 6:38 sponsor: Threadify 7:53 X pays creators to post video 9:22 more Codex usage, but no number 10:02 Claude Code answers sooner 10:54 move your AI memory into Grok Bot 11:55 run your own model bake-off 12:42 who won: old GPT vs new GPT 13:44 the prompt (full text below) thanks to today's sponsor, my software Threadify - your lead generation agent: https://www.threadify.app/home?utm_source=youtube&utm_medium=video&utm_campaign=lab-0024&utm_content=sponsor want to sponsor a future episode? sponsors@lennysaibuilders.com watch the full episode: https://youtu.be/eIGJmUUqUr8

What is Lenny’s AI Builders?

less scrolling. more “oh shit, i could use that.”

i’m Lennox. i dig through the AI updates worth your time, then test tools, models and agents on real work. what worked, what broke, and what you can try yourself.

for people making products, content and useful systems with AI. you don’t need to write code to build something worth using. grab the field notes for prompts, steps and the bits to watch out for: https://lennoxsaint.com/lab

this feed also keeps the earlier L E S S O N S episodes from my journey building with AI.