Marc Andreessen’s anti-sycophancy prompt has millions of views. It’s the one the smartest people in tech are using right now. Here it is — word for word — plus my tighter, plain-English rewrite. Save them both.
Why This Went Viral
In May 2026, Marc Andreessen — cofounder of Andreessen Horowitz (a16z) — posted his favorite custom prompt on X. It told AI to stop sucking up, push back when you’re wrong, and lead with the strongest counter-argument before agreeing.
It hit a nerve. OpenAI had just rolled back GPT-4o for being “too sycophant-y.” Power users had been begging for a real fix. The post went past 2M views in days.
Use one of these prompts as your Project Instructions in Claude (or your custom GPT system prompt) and you’ll feel the difference in the first answer.
Aggressive on purpose. If you want pure pushback with no softening, use this one.
Same anti-sycophancy backbone. Cleaner, less aggressive, easier to actually live with day to day.
Place 01
Claude Project Instructions. Best spot. Every chat in that project picks it up automatically.
Place 02
Custom GPT system prompt. Paste into the “Instructions” field when you create a GPT.
Place 03
Top of any new chat. If you’re not in a project, paste it as your first message.
When NOT to use this
Creative brainstorming. You want generative energy, not pushback — turn it off.
Emotional support. Don’t ask the anti-sycophancy AI for kind words on a hard day. Different tool, different prompt.
First-draft ideation. Early in a creative process, you need encouragement to get unstuck. Bring this prompt back when it’s time to pressure-test.
Try it on your last conversation
Open the last serious Claude or ChatGPT conversation you had. Paste one of these prompts at the top of a fresh chat, then ask the same question. Compare. The first time you do this, you’ll see how much you’ve been getting buttered up.
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