What is a system prompt?
A system prompt is the instruction given to an AI model before the conversation starts.
It sets the model's role, tone, constraints, and behavior — making it act as a
Senior Engineer, Code Reviewer, or any other persona you need.
How to use a persona
Click Copy prompt on any persona, then paste it as the system prompt
in Claude, ChatGPT, Gemini, or any other LLM interface. The model will adopt that
persona for the conversation.
Custom personas
Click Add custom to create your own persona with a name, description,
and system prompt. Custom personas are saved in your browser's localStorage — they
persist across sessions and never leave your device.
Why bother with a persona at all?
"Act as a senior engineer" gets you a vague impression of one. A good persona prompt is
specific: it names the role, the tone, what to prioritize, and what to push back on.
That's the difference between an assistant that pads every answer with disclaimers and
one that reviews your code like a colleague who's seen your stack before. The 20 personas
here are written that way — pick one, paste it, and skip the ten minutes of prompt
fiddling you'd otherwise repeat every session.
Where these fit in real work
- Code review: load the Code Reviewer persona into a fresh chat before dropping in a diff — you get findings, not compliments.
- Docs and writing: the Technical Writer persona keeps output structured and jargon-checked instead of generically enthusiastic.
- Consistency with yourself: once you've tuned a prompt that works, save it as a custom persona so tomorrow-you starts from the same instructions as today-you.
FAQ
Do these work with any model?
Yes. A system prompt is plain text — paste it into Claude, ChatGPT, Gemini, or a local model, anywhere that accepts a system or custom-instructions field.
Where are my custom personas stored?
In your browser's localStorage. They persist between visits on that device, never sync anywhere, and disappear if you clear site data — so keep a copy of prompts you care about.
Can I edit a built-in persona?
Copy its prompt, tweak the text, and save the result with Add custom. The built-ins stay untouched, and your variant sits alongside them.
// huntermussel
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