Here's the part nobody likes to mention: every chatbot makes things up, and it happens more than you'd guess. On factual, citation-heavy questions, studies put the hallucination rate for models like GPT-4o somewhere around 15 to 20 percent. Claude is not magically immune to that, but a lot of people find they trust its answers more, they prefer how it writes and reasons, and they're quietly moving over.

The annoying part of switching is that ChatGPT already knows you. Months of chats, your projects, your preferences, the way you like answers. Start fresh in Claude and you lose all of it. This prompt fixes exactly that. It pulls everything ChatGPT has learned about you and turns it into a system prompt you paste straight into Claude, so Claude picks up right where you left off. Start to finish it takes about 30 seconds.

The switch prompt

Copy this whole thing. You'll paste it into ChatGPT in a second.

The switch prompt
You are about to help me migrate from ChatGPT to Claude. Your job is to compile everything you know about me into a portable profile, then convert it into a system prompt I can paste into Claude's custom instructions so Claude picks up exactly where you left off.

Use everything available to you: your saved memories about me, my custom instructions, and patterns you've observed across our chat history, my goals, projects, preferences, communication style, expertise level, recurring topics, and how I like answers formatted.

Output EXACTLY two sections, formatted in markdown, nothing before or after them.

---

## SECTION 1: MY INFORMATION

Write a complete profile of me organized under these headings. Be specific and detailed, pull real facts, not generic filler. If you genuinely don't know something, skip it rather than inventing it.

**Who I am:** Name, age/life stage, location, occupation, education, and anything defining about my situation.

**What I'm working on:** Every active project, business, job, or goal you know about. Include names, tools, tech stacks, clients, deadlines, and current status of each.

**My expertise:** What I already know well (so Claude never over-explains it) and what I'm still learning (so Claude knows where to add detail).

**My preferences:** How I like responses, length, tone, formatting, level of detail, things that annoy me, things I've corrected you on repeatedly.

**My interests:** Hobbies, topics I keep coming back to, people or brands I follow, things I care about outside work.

**Context that matters:** Anything else important, my schedule, constraints, relationships relevant to my work, past decisions, recurring frustrations, long-term ambitions.

**Ongoing threads:** Unfinished conversations, decisions I was weighing, and things I said I'd come back to.

---

## SECTION 2: SYSTEM PROMPT FOR CLAUDE

Now rewrite all of that as a system prompt written in second person, addressed TO Claude, that I will paste into Claude's custom instructions. It should:

1. Open with: "You are my personal AI assistant. Here is everything you need to know about me from day one:"
2. Contain every meaningful fact from Section 1, rewritten as direct instructions and context (e.g. "The user runs X and is currently building Y. Always assume Z.")
3. Include explicit behavioral instructions based on my preferences: how to format answers, what tone to use, what to never do, what to always do.
4. Include a "Current priorities" block listing my top 3-5 active projects so Claude knows what matters most right now.
5. End with: "Act as if we have been working together for months. Never ask me to re-explain background you already have here."

Make Section 2 dense and complete, it should stand alone. Someone reading only Section 2 should be able to assist me as well as you can.

Do not summarize, do not shorten, do not add commentary. Output the two sections and nothing else.

How to use it (30 seconds)

  1. Open ChatGPT, paste the prompt in, and press enter. Use the account where you actually have your history and memory, that's what it pulls from.
  2. Let it finish, then copy the entire output. You'll get two parts: a full profile of you, and a ready-to-paste system prompt.
  3. Go to Claude, open settings, then personalization, and find custom instructions.
  4. Paste the output in there and hit save. That's it.

From then on, Claude answers like it has known you for months. It already has your projects, your style, and your priorities, so you skip all the re-explaining that makes a fresh AI feel useless for the first week.

Two things worth knowing

  • It only knows what ChatGPT knows. If your ChatGPT memory is thin, the profile will be thin. The more you've actually used it, the better this comes out.
  • Read Section 1 before you paste it. It's a mirror of what ChatGPT thinks about you, which is genuinely interesting, and you can trim anything you'd rather not carry over into Claude.
The switch itself was never the hard part. Losing everything the old tool learned about you was. This makes that cost basically zero.

You don't have to fully leave ChatGPT to do this. Even if you just want to test-drive Claude, this gets you a version that already understands you, instead of a blank slate.

Run it once, paste it into Claude, and see if you get why people are making the move.
– Anir

If this is the kind of AI thinking you want working on your own business, apply to work with me. And to catch the next breakdown, join the newsletter.