System Prompt Generator
100% PrivateAI & Prompt ToolsBuild the system prompt behind a chatbot or assistant from persona, rules and behavior fields.
Runs entirely in your browser. Your input is not uploaded to Ovatly or anywhere else.
Template assembly only: your fields are arranged into a system prompt in the format you choose. Nothing is written by an AI model.
Fill in at least the persona field, and the generated system prompt will appear here.
- 1Write the persona: who the assistant is, in one phrase.
- 2Add its area of expertise and its always-follow rules, one per line.
- 3Add output rules (length, language, structure) and optionally an example exchange.
- 4Pick plain, Markdown or JSON and copy the generated system prompt.
Persona: "a concise technical support agent"; Expertise: "home Wi-Fi routers"; Rules: "Never guess a password" and "Ask one question at a time"; Output rules: "Answer in plain English" and "Keep answers under 120 words". Plain output: You are a concise technical support agent. Your area of expertise is home Wi-Fi routers. Rules you always follow: 1. Never guess a password 2. Ask one question at a time How you format your answers: 1. Answer in plain English 2. Keep answers under 120 words
- This is template assembly: the generator arranges your fields and never invents rules you did not write.
- In JSON format the fields become an object under a system role, with quotes and newlines escaped by JSON.stringify, so it is safe to paste into an API payload.
- A system prompt guides a model; it cannot guarantee behavior. Test the result with real questions before relying on it.
It is the standing instruction given to a model before the conversation starts. It sets identity, expertise, rules and answer format for every reply that follows.
About this tool
The System Prompt Generator builds the instruction block that sits behind a chatbot or AI assistant: persona, expertise, rules, output rules and an example of expected behavior. Fill in the behavior fields and choose plain text, Markdown or JSON output; the tool assembles them in a consistent structure with correct formatting and, for JSON, correct escaping handled for you.
Related tools
Part of Ovatly's free tools in AI & Prompt Tools.