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System Prompt Generator

Write system prompts that define AI behavior and personality

System Prompt Generator — How It Works

The system prompt generator write system prompts that define AI behavior and personality.

What It Does

Free AI system prompt generator. Create professional system prompts that set the role, personality, constraints, and output format for AI assistants and chatbots.

When To Use It

Use this tool whenever you need write system prompts that define AI behavior and personality. Results are best when inputs are specific and contextual rather than vague.

Tips For Best Results

Provide concrete context — audience, format, constraints — rather than single-word inputs. The more signal the tool has, the more useful the output.

$ faq

What is a system prompt? ▸
A system prompt is the initial instruction that defines how an AI behaves. It sets the role, personality, rules, and boundaries before any user interaction.
Where do I put the system prompt? ▸
In API calls, it goes in the 'system' message role. In ChatGPT custom GPTs, it goes in the Instructions field. In Claude, it's the system parameter.
How long should a system prompt be? ▸
300-800 words covers most use cases. Include enough detail for consistent behavior without being so long that key instructions get lost.
Should I include examples? ▸
Yes. 2-3 example interactions show the AI exactly how to respond. They're more effective than abstract rules for defining behavior.
Can I use this for custom GPTs? ▸
Yes. The output works directly as Instructions for OpenAI custom GPTs, Claude projects, or any AI platform that supports system-level instructions.