If you find yourself repeatedly telling ChatGPT to 'be concise,' 'write in Python,' or 'ignore previous instructions,' you are wasting valuable time. ChatGPT Custom Instructions is a powerful feature that allows you to set persistent preferences so the AI remembers your context, goals, and preferred output style across every new chat session.

Step 1: Accessing Custom Instructions in ChatGPT

To begin, you need to locate the Custom Instructions menu within your account settings. This feature is available to both Free and Plus users on the web and mobile app.

• On Web: Click on your profile name or icon in the bottom-left (or top-right) corner and select 'Customize ChatGPT'.
• On Mobile: Tap the two lines to open the sidebar, tap your name at the bottom, and select 'Custom Instructions'.

Step 2: Defining Your Profile (The 'What' Section)

The first box asks: 'What would you like ChatGPT to know about you to provide better responses?' This is where you provide context about your professional and personal identity.

To optimize this section, consider including:

• Your Role: (e.g., 'I am a Senior Software Engineer specializing in React.')
• Your Projects: (e.g., 'I am currently building a SaaS platform for fitness tracking.')
• Your Tools: (e.g., 'I use VS Code, Jira, and GitHub for my daily workflow.')
• Location/Context: (e.g., 'I live in the UK, so use British English and Metric units.')

Step 3: Defining Response Behavior (The 'How' Section)

The second box asks: 'How would you like ChatGPT to respond?' This section controls the tone, length, and format of the AI's output. By setting these, you eliminate the need for long 'meta-prompts' every time you start a chat.

Highly effective instructions include:

• Tone: (e.g., 'Maintain a professional yet conversational tone.')
• Format: (e.g., 'Always use Markdown. Use tables for data comparisons.')
• Level of Detail: (e.g., 'Be concise and skip the introductory fluff. Give me the solution first, then explain.')
• Coding Standards: (e.g., 'When writing code, always include comments and follow PEP 8 standards.')

Step 4: Using 'Act As' Personas for Specific Workflows

One of the best ways to use Custom Instructions is to force ChatGPT into a perpetual persona. For example, if you are an SEO expert, your instructions might look like this:

"Always act as an SEO strategist. When I provide a topic, suggest 5 long-tail keywords, a meta description under 160 characters, and an H1 tag. Never apologize for being an AI."

By saving this, every prompt you enter will be processed through the lens of an SEO professional without you having to ask.

Step 5: Testing and Refining Your Instructions

Once you have filled out both boxes, ensure the 'Enable for new chats' toggle is turned ON and click Save. Open a new chat and type a simple prompt to see the difference.

Pro-Tip: If you need to switch tasks (e.g., moving from coding to creative writing), you can return to the Custom Instructions menu and update them. Note that changes only apply to new chats; existing conversations will retain the instructions they were started with.

Step 6: Troubleshooting Custom Instructions

If ChatGPT seems to be ignoring your instructions, check the following:

• Character Limit: You are limited to 1,500 characters per box. Ensure your instructions are not cut off.
• Conflicting Prompts: If you give a specific instruction in a chat (e.g., 'Write this informally') that contradicts your Custom Instructions (e.g., 'Always be formal'), the direct prompt will usually take precedence.
• New Chat Requirement: Remember that saving new instructions does not update 'active' chats. You must start a new session for the changes to take effect.

💡 Pro Tip: Keep your software updated to avoid these issues in the future.