This ChatGPT tutorial explains how to enable and write “Custom Instructions,” and how to make ChatGPT consistently respond in your preferred tone and rules over the long term. Once set up, ChatGPT will follow your preferences by default in new conversations, so you don’t have to repeat them each time.
1. Enable ChatGPT Custom Instructions on the Web
Open ChatGPT in your browser, click your profile icon or the menu in the lower-left corner, and go to “Settings.” In Settings, find “Custom instructions” (some interfaces may show it as “Customize ChatGPT”).
After entering, you’ll usually see two input boxes: one helps ChatGPT understand you (background, goals, role), and the other specifies how you want ChatGPT to respond (format, tone, length, whether to include steps). After saving, ChatGPT will apply these instructions to newly created conversations.
2. Set It Up in the Mobile App so ChatGPT Answers the Same Way Anywhere
Open the ChatGPT app, go to “Settings,” find “Custom Instructions,” and toggle it on. The mobile setup works the same way as the web version: fill in “About you” and “How you want ChatGPT to respond.”
It’s recommended to make the “output format” more explicit on mobile—for example: “Give the conclusion first, then a step-by-step checklist, and finish with key notes.” This helps ChatGPT produce consistent, copy-ready output in mobile scenarios.
3. How to Write Better Custom Instructions: Three Simple Templates
The first type is your role and goal—for example: “I work in content operations and often write tutorial-style articles. My readers are beginners.” This helps ChatGPT default to clearer, more beginner-friendly explanations.
The second type is output rules—for example: “Use bullet points, keep each point under two sentences, and include examples when necessary.” The third type is boundaries and constraints—for example: “Don’t make up data. If you’re not sure, say you’re not sure and provide a way to verify.” This can significantly reduce made-up or overfilled details.
4. Common Issues: What to Do If It Doesn’t Work or You Can’t Find the Setting
If you notice ChatGPT still isn’t responding as requested, first confirm whether you’re testing in an old conversation; Custom Instructions are typically more reliable in “new chats.” You can also add a quick reminder at the start of a new chat like, “Follow my Custom Instructions,” as a strong prompt.
If you can’t find the option in Settings, update the ChatGPT app first, or refresh the webpage and log in again; in some network environments, incomplete UI loading can also cause options to be missing. Another thing to check is whether you’ve enabled “Temporary Chat,” which reduces personalization—useful when you don’t want long-term preferences to affect the conversation.
