Claude Projects vs ChatGPT Custom GPTs

Both Claude Projects and ChatGPT Custom GPTs let you create specialized AI assistants with custom instructions and knowledge. But they work differently, and each has strengths the other lacks. This lesson helps you decide when to use which.

Feature Comparison

Feature	Claude Projects	ChatGPT Custom GPTs
Custom instructions	Yes — detailed text instructions	Yes — via GPT Builder
Knowledge files	Upload PDFs, docs, code, data	Upload files as knowledge
Conversation history	Multiple conversations per project	One thread per GPT session
Sharing	Team sharing (Team/Enterprise)	Public via GPT Store
API connections	No	Yes — custom actions via API
Image generation	No	Yes — DALL-E integration
Web browsing	No	Yes — real-time web search
Code execution	No (Artifacts show previews)	Yes — Python in sandbox
Live content preview	Yes — Artifacts panel	No
Setup method	Text-based instructions	Conversational GPT Builder
Iterative content	Artifact versioning	Conversation-based

Where Claude Projects Excel

1. Deep Document Work

Claude's 200K token context window and Projects' persistent knowledge files make it the stronger choice for document-heavy workflows:

• Analyzing 100+ page contracts or reports
• Comparing multiple research papers
• Working with large codebases
• Processing detailed technical specifications

Example: Upload a 300-page regulatory document to a Claude Project and reference it across dozens of conversations over weeks. With a Custom GPT, you would need to re-upload or chunk the document each session.

2. Writing Quality

Claude's writing tends to be more measured and natural. Combined with Project instructions that define your brand voice:

• Blog posts that do not sound AI-generated
• Professional reports with appropriate nuance
• Academic writing with proper citations
• Content that follows specific style guides consistently

3. Multi-Conversation Workflows

Claude Projects support multiple conversations within the same project context. This is ideal for workflows that span many sessions:

Week 1: Research and outline Week 2: Draft chapters 1-3 Week 3: Draft chapters 4-6 Week 4: Review and revise

Each conversation is separate but shares the same instructions and knowledge files.

4. Content Iteration with Artifacts

When you need to iterate on code, documents, or diagrams, Artifacts provide a dedicated panel:

• See live previews of HTML and React components
• Compare versions side by side
• Export finished content directly
• No content lost in chat scroll

Where ChatGPT Custom GPTs Excel

1. Public Distribution

Custom GPTs can be published to the GPT Store for anyone to use. This is a major advantage if you want to:

• Create tools for your audience or customers
• Build a portfolio of specialized assistants
• Share domain-specific GPTs with a community

Claude Projects are workspace tools — they are not designed for public distribution.

2. API Integrations

Custom GPTs support "Actions" — API connections that let the GPT interact with external services:

• Pull data from your CRM
• Create tasks in project management tools
• Look up inventory or pricing in real-time
• Post to social media platforms

Claude Projects cannot connect to external APIs.

3. Code Execution

ChatGPT's Code Interpreter can execute Python code in a sandbox:

• Run data analysis on uploaded CSV files
• Generate charts and visualizations
• Process and transform data
• Test code logic in real-time

Claude can write code and preview web content in Artifacts, but it cannot execute Python or other backend languages.

4. Image Generation

Custom GPTs include DALL-E for image generation:

• Create illustrations for blog posts
• Generate product mockups
• Design social media graphics
• Produce diagrams and infographics

Claude cannot generate images.

5. Web Browsing

Custom GPTs can browse the web for current information:

• Research recent events or trends
• Fact-check claims against current sources
• Find and summarize recent articles
• Check competitor websites

Claude cannot access the internet.

Decision Framework

Use this framework to choose the right tool:

Choose Claude Projects When:

• You work with long or complex documents
• Writing quality and brand voice matter
• You need multi-session workflows with persistent context
• You iterate on code, documents, or diagrams (Artifacts)
• Your project is internal (not for public distribution)

Choose ChatGPT Custom GPTs When:

• You want to publish the assistant publicly
• You need API integrations with external services
• You need to execute code and generate visualizations
• You need image generation
• You need access to current information via web browsing

Use Both When:

Many professionals use both tools in complementary workflows:

Task	Tool	Why
Draft a report from uploaded research	Claude Project	Large context, better writing
Generate charts from the report's data	ChatGPT Custom GPT	Code Interpreter for charts
Create cover images for the report	ChatGPT Custom GPT	DALL-E integration
Iterate on the report's HTML template	Claude Project	Artifacts for live preview
Publish a simplified version as a public tool	ChatGPT Custom GPT	GPT Store distribution

Migration Tips

Moving from Custom GPTs to Claude Projects

If you have existing Custom GPTs and want to try Claude Projects:

1. Copy your GPT's instructions — they translate directly to Claude Project instructions
2. Re-upload knowledge files — same files work in both platforms
3. Adjust for tone differences — Claude tends to be less enthusiastic by default, so remove instructions that say "be energetic" or "use exclamation points"
4. Take advantage of multi-conversation — instead of one long thread, use separate conversations for different phases

Moving from Claude Projects to Custom GPTs

1. Simplify instructions — the GPT Builder works best with shorter, clearer instructions
2. Consider Actions — if your Project workflow involves manual data lookups, you might automate them with API Actions
3. Plan for distribution — if you want to share publicly, Custom GPTs are the way

Key Takeaways

• Claude Projects excel at document-heavy work, writing quality, multi-conversation workflows, and content iteration via Artifacts
• Custom GPTs excel at public distribution, API integrations, code execution, image generation, and web browsing
• Choose based on your primary need: deep work (Claude) vs. connected and shareable tools (Custom GPTs)
• Many professionals use both — Claude for drafting and analysis, ChatGPT for execution and distribution
• Instructions and knowledge files transfer between platforms with minimal changes