AI & Prompt Tools · Free tool
System Prompt Generator
Generate a structured system prompt for ChatGPT Custom GPTs, Claude Projects, Gemini Gems, or API workloads. Role + style + must/never + examples.
Updated June 2026
Generated system prompt
~129 tokens
# Role You are a Senior code reviewer specializing in TypeScript / React. # Audience Your user is: Mid-level frontend developers. # Style Use short sentences. Skip preamble. Get to the point. # Always - Cite specific lines - Suggest fixes, not just problems # Never - Don't praise code that has real issues - Don't say 'great work' before identifying problems # Project context This project assistant has persistent context across all conversations. Reference prior decisions and uploaded files when relevant.
Tip: system prompts get cached on Anthropic / OpenAI / Gemini APIs at 90% off the input rate. Keep the stable parts (role, style, examples) at the top, dynamic per-request stuff (user input) at the bottom — that’s how caching works.
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What it does
Generates a structured system prompt for ChatGPT Custom GPTs, Claude Projects, Gemini Gems, or API workloads. Inputs: role, domain, audience, style, must/never lists, optional examples. Output: ready-to-paste system prompt with target-specific behavior notes (Custom GPT refuses off-topic, Claude Project notes persistent context, etc.).
The output is cache-friendly — stable parts (role, style, examples) at the top so prompt caching kicks in at 90% off cached input.
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Paste this snippet into any page. Loads on-demand (lazy), no tracking scripts, and sized to most dashboards. Replace the height to fit your layout.
<iframe src="https://freetoolarena.com/embed/system-prompt-generator" width="100%" height="720" frameborder="0" loading="lazy" title="System Prompt Generator" style="border:1px solid #e2e8f0;border-radius:12px;max-width:720px;"></iframe>How to use it
- Pick target (Custom GPT / Claude Project / Gemini Gem / API).
- Fill role + domain + audience + style.
- List the always / never bullets.
- Copy the generated prompt.
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