Custom Instructions
Custom Instructions are persistent configuration settings in ChatGPT that allow users to define how the AI should behave across all conversations. Rather than repeating context, preferences, or role information in each new chat, users specify these details once in their account settings, and ChatGPT applies them automatically to subsequent interactions. This reduces redundancy and helps maintain consistent behavior and response style throughout multiple conversations.
Configuration
Users access Custom Instructions through their ChatGPT account settings, typically entering information in two sections: one for describing who they are and what they do, and another for specifying how they want ChatGPT to respond. These settings are then applied to all new conversations unless the user explicitly disables them. The instructions function as a form of persistent context that shapes the model’s behavior without requiring manual input at the start of each chat.
Applications
Custom Instructions are commonly used to establish professional roles (such as a teacher or developer), specify desired communication styles (formal or casual), indicate expertise level for explanations, or set preferences for response length and format. They enable users to create a more personalized experience and can improve efficiency by eliminating the need to re-establish context in repetitive conversations. However, the effectiveness of Custom Instructions depends on the clarity and specificity of what users configure.
Source Notes
- 2026-04-07: How to Set Up ChatGPT, Claude & Gemini for Legal Work
- 2026-04-22: AI Agent Skills · ▶ source
- 2026-04-28: ChatGPT · ▶ source
- 2026-05-01: Modern AI Agentic Harness: Architecture, Components, and Framework Differences · ▶ source