As more people migrate from ChatGPT to Claude, especially for content writing and analysis, one question keeps coming up: What happens to my custom GPTs?
If you’ve built custom GPTs over the past year, you’ve invested time crafting instructions, uploading knowledge files, and fine-tuning prompts. The idea of abandoning all that work is enough to stop the switch entirely.
Good news: you don’t have to abandon them. This article explains exactly how to recreate your custom GPTs in Claude using Skills and Projects—and when it makes sense to keep both tools running.
If you’re considering the switch but haven’t made it yet, read about my experience switching from ChatGPT to Claude after three years.
What Are Custom GPTs?
Custom GPTs are specialized versions of ChatGPT that combine four components: system instructions (specialized prompts that define behavior), knowledge files (uploaded documents for reference), conversation starters (saved prompts), and built-in capabilities (web search, image generation, code execution). Most custom GPTs are essentially well-crafted prompts paired with optional reference documents.
That’s it. No magic. Most custom GPTs are just good prompts plus optional documents.
Additionally, there are two types: Public GPTs and Personal GPTs.
If you need a refresher on how custom GPTs are built, check out our complete guide to building custom GPTs for marketers.
What Happens to Your Custom GPTs if You Go to the Free Plan?
When you cancel Plus and go to the free plan, all GPTs you created (private and public) remain stored on your account. But none of them are active on the free plan:
- You cannot edit them
- You cannot run them yourself
- Your public GPTs are not usable by others in the marketplace
When you upgrade back to Plus, all GPTs are restored exactly as they were (editable + runnable + public ones work again).
Claude's Alternatives: Skills and Projects
Claude offers two main ways to replace custom GPTs: Skills and Projects. Here’s when to use each.
Skills
Skills are reusable instruction sets stored in .md files. Think of them as portable custom GPTs that work across all your conversations.
What are .md files?
Markdown files are plain text files with simple formatting. A .md file is just like a .txt file, but with special syntax for headers, lists, and formatting. For example:
- # Title – creates a header
- **bold** – makes text bold
- – item – creates a bullet point
How to create .md files?
Option 1: Download from Google Docs
If you have your custom GPT’s system prompt in a Google doc:
- Open the document
- Go to File > Download
- Choose Markdown (.md)
Option 2: Export from Word
If you have your custom GPT’s system prompt in a Word document:
- Open the document in Microsoft Word
- Go to File > Save As
- Change “Save as type” to “Plain Text (.txt)”
- Save the file
- Rename the file extension from .txt to .md
Option 3: Ask Claude to Convert It
The easiest method:
- Upload your Word document (or paste your system prompt) to Claude
- Ask: “Convert this into a properly formatted .md file for a Claude Skill”
- Claude will format it with the correct Markdown syntax
- Copy the result into a text editor and save as filename.md
When to use Claude Skills?
When you want the same instructions available across multiple projects or conversations. Perfect for specialized writing styles, analysis frameworks, or any workflow you use repeatedly.
How to use Skills in Claude?
- Create your .md file with instructions
- Upload it to Claude
- Reference it in your conversation when needed
- Claude will follow those instructions
How to reference a Skill in a conversation?
Claude will understand even if you use generic language like “ego-centric language”. However, for best results, reference your skill’s name literally. Using the exact skill name helps Claude identify which instructions to follow, especially if you’ve uploaded multiple Skills.
Projects
Projects are Claude’s answer to persistent context. They hold instructions, documents, and conversation history in one place.
ChatGPT has Projects too, but they work differently. ChatGPT Projects are mainly for organization. Claude Projects actually inject custom instructions and documents into every conversation within that project.
When to use Projects?
When you’re working on ongoing tasks that build on previous conversations. Research projects, content series, client work—anything where context matters over time.
The Reality Check on Other Features
Artifacts, Styles, extended context windows, web search—these are genuinely great Claude features. But they’re not custom GPT replacements. They’re bonuses.
The actual replacements are Skills and Projects. Everything else just makes Claude better to work with.
For a detailed comparison of how Claude and ChatGPT handle content creation differently, see our Claude vs ChatGPT guide.
Hands-On: Converting the "Ego Check" Custom GPT
Let me show you exactly how to migrate a real custom GPT. I’m using my “Ego Check” messaging coach as an example. It scores how customer-centric your copy is. Lower score, less ego — more focus on your audience.
Step 1: Turn the prompt file into an .md file as described above
Step 2: Choose your approach: Skill or Project?
For Ego Check, I chose a Skill because:
- I use it across different clients and projects
- The instructions don’t need to change
- I don’t need accumulated conversation history
- I want it available in any Claude conversation
If this were a custom GPT for a specific client with uploaded brand guidelines and accumulated research, I’d use a Project instead.
Step 3: Upload and Use the Skill
In Claude:
- Go to Settings > Capabilities > Skills > Add
- Add your .md file
Once uploaded, the skill is available across all your conversations.
Test and Compare
I ran the same blog post through both the Ego Check custom GPT and the Claude Skill to compare results.
The functionality transfers perfectly to Claude Skills. Both versions:
- Applied the scoring framework correctly
- Identified similar ego-centric patterns
- Provided detailed breakdowns by criterion
- Offered actionable feedback
The scores differ slightly (63 vs 62) because the underlying models evaluate differently, but both produce valuable, usable analysis. The Skill works exactly as the custom GPT did.
Claude Skills vs. Projects: When to Use Each?
Use a Skill when:
- You want the same instructions available across different projects or contexts
- The instructions are a reusable framework or methodology
- You need flexibility to turn it on/off per conversation
- Example: A writing style guide, an analysis framework, a scoring rubric
Use a Project when:
- You’re working on a specific, ongoing piece of work
- You need accumulated conversation history and context
- You have client-specific or project-specific documents
- The instructions only apply to this one body of work
- Example: A specific client account, a book you’re writing, a research project
Bottom Line
Your personal custom GPTs aren’t locked in ChatGPT forever. Skills and Projects can replace most of them.
Public custom GPTs in the GPT Store? Those genuinely are locked in. If you’ve created some or use other publishers’ GPTs, keep a ChatGPT subscription.
Start with one migration. See how it feels. You’ll quickly learn whether your custom GPT was valuable because of its instructions (easy to migrate) or because of ChatGPT-specific features (harder to replicate).
The hybrid approach is fine. Use the best tool for each job. Don’t overthink it.
Pick one custom GPT this week. Try recreating it as a Skill or Project. See what happens.
Frequently Asked Questions
Can I migrate custom GPTs from the ChatGPT Store that I didn't create?
No. Public custom GPTs from the GPT Store that were created by others can’t be migrated because you don’t own the instructions or underlying prompts. You can only migrate personal custom GPTs that you built yourself. If you rely heavily on certain public GPTs, you’ll need to keep your ChatGPT Plus subscription to continue using them.
What's the difference between Claude Skills and Projects, and which should I use?
Skills are reusable instruction sets that work across all your conversations—perfect for frameworks, analysis methods, or writing styles you use repeatedly. Projects are workspaces that maintain persistent context, instructions, and documents for specific ongoing work—ideal for client accounts, book projects, or research that builds over time. Use Skills for “how to do something,” Projects for “this specific thing I’m working on.”
Will my custom GPT work exactly the same in Claude?
The core functionality—instructions and uploaded documents—transfers perfectly. Both Claude Skills and custom GPTs follow specialized prompts and reference knowledge files. The outputs may differ slightly because Claude and ChatGPT are different models with different reasoning approaches, but in most cases, Claude’s analysis is equally good or better. Custom GPTs with Actions (API integrations) are the exception—those can’t be directly replicated in Claude yet.
Do I need to keep my ChatGPT Plus subscription after migrating my custom GPTs?
It depends on your use case. If all your custom GPTs are personal ones you built, you can cancel ChatGPT Plus and migrate them to Claude. However, if you’ve published public custom GPTs that serve as lead magnets or if you regularly use public GPTs from the store, keeping both subscriptions makes sense. Most people end up with a hybrid approach—using each tool for its strengths.
