Answer 5 quick questions — get ready-to-paste custom instructions for ChatGPT and a system prompt for Claude. 100% free, no API key.
Custom instructions are two persistent fields in ChatGPT that let you describe yourself and set response preferences once — and have them apply to every conversation automatically. Think of them as a permanent system prompt that you control.
Good custom instructions eliminate repetitive setup at the start of each chat ("I'm a developer, keep it technical, no fluff") and make ChatGPT substantially more useful for your specific workflow.
ChatGPT custom instructions are two persistent text fields that tell ChatGPT about you and how you want it to respond. They are sent automatically with every message so you do not have to repeat your preferences each conversation.
Go to ChatGPT settings → Personalization → Custom instructions. Paste your text in the two fields: "What would you like ChatGPT to know about you?" and "How would you like ChatGPT to respond?" This generator creates the text for both fields automatically.
Yes. This tool generates a Claude-formatted system prompt that you can paste into Claude Projects (Settings → System Prompt) or any Anthropic API call. The generator produces both ChatGPT and Claude formats.
No. The custom instructions generator is 100% free and works entirely in your browser. No account, no API key, no data sent to any server.
Good custom instructions cover: (1) Who you are and your expertise level, (2) What you use AI for most often, (3) Preferred tone (formal vs. casual), (4) Detail level preferences, (5) Output format rules, and (6) Any must-follow rules like "never add a preamble" or "always show code examples."