AI System Prompt Generator
Write the instructions that define how an AI assistant behaves in every conversation. Give it a name and purpose, describe the users, list what it can do and what it must never do, add the facts it should rely on, and choose its tone, answer style and what to do when it does not know. An optional security block tells the assistant to treat user and document text as data and to keep its instructions private.
- Runs in your browser
- No sign-up
- Free to use
How to use AI System Prompt Generator
- Describe the purpose and users.
- List what it can and must not do.
- Add reference facts.
- Choose style and uncertainty behaviour, then copy.
AI System Prompt Generator features
Clear boundaries
Allowed and forbidden actions.
Reference facts
Grounding in your information.
Uncertainty rules
Say so, ask or escalate.
Injection resistance
Optional security block.
Three layouts
Markdown headings, XML tags or plain labels.
Private
Built in your browser; nothing is sent to an AI service.
When to use AI System Prompt Generator
- Custom GPTs and Claude projects.
- Support chatbots.
- Internal assistants.
- Tutoring bots.
AI System Prompt Generator FAQ
Where does a system prompt go?
In the system (or developer) message of a chat API, or the instructions field of an assistant builder.
Can it stop all misuse?
No prompt is perfect. Combine it with access controls and review, and test with adversarial questions.
Why list forbidden actions?
Explicit boundaries – no passwords, no promises – prevent the most damaging mistakes.
Markdown or XML tags?
Both work with modern models. XML tags such as <task> and <context> are recommended by Anthropic for Claude and help any model separate instructions from data; Markdown headings are easier to read.
Designing assistant behaviour
A system prompt is the assistant’s job description. The more concrete it is about scope, facts and boundaries, the more consistent the assistant becomes.
Reference facts reduce invented answers: an assistant that knows your support hours does not need to guess them.
This tool does not call an AI model. It turns your answers into a well-structured prompt in your browser, so it costs nothing, works offline once loaded and never sends your text anywhere. Paste the result into ChatGPT, Claude, Gemini, Copilot or any other assistant, or into the system message of an API call.
Good prompts are specific about the task, the context the model cannot know, the audience and the shape of the answer. The fields on this page cover exactly those parts; leave optional fields empty when they do not apply, and the prompt stays short.
Review the answer you get: language models can be confidently wrong, especially about facts, numbers, names and recent events. Ask for sources or mark claims to check, and keep personal or confidential data out of prompts unless your organisation allows it.