Structured System Prompt Generator
Build structured AI system prompts with Role, Context, Task, Constraints, and Output Format fields.
主な特徴とプライバシー保証
- ✓ 100%ブラウザ内完結: データは端末外に出ず、外部サーバーに送信されることはありません。
- ✓ リアルタイム高速出力: ネットワーク遅延ゼロ、入力と同時に即時反映・高速コピー。
- ✓ 永久無料＆制限なし: 会員登録不要、課金なし、1日の利用制限も一切ありません。
- ✓ 標準規格準拠: RFC、ISO、W3Cウェブ標準仕様に厳密に準拠して設計されています。
Build professional AI system prompts for ChatGPT & Claude
Define AI agent personas, provide background context, specify strict rules, and control output formatting for consistent LLM responses.
技術仕様とアーキテクチャ
- Execution Environment:
- 100% Client-Side Browser Sandbox
- Data Privacy:
- Zero Server Storage / No Tracking
- Processing Speed:
- Real-time local CPU execution
- Cross-Platform:
- Works on Windows, macOS, Linux, iOS & Android
Prompt Engineering & Token Estimation Engine
LLM utilities evaluate prompt lengths, structure system instructions, and calculate approximate token counts based on byte-pair encoding (BPE) algorithms used by OpenAI, Anthropic, and Google models. This helps prevent token budget overflows and optimizes monthly API expenditure.
Provide Input
Enter, paste, or upload your data into the input field above.
Configure & Process
The tool immediately processes your input in real time according to your chosen settings.
Copy or Save
Use the Copy button to copy the output to your clipboard, or download the result to your device.
主な利用シーン
- Create system prompts for developer assistants, coding agents, and content writers
- Establish strict guardrails and formatting rules for AI API integrations
- Build instruction sets for Custom GPTs and Claude AI Assistants
関連のおすすめツール
連携ツール・次のステップ
Structured System Prompt Generatorと合わせてよく使われる便利な開発者ユーティリティ
Prompt Token Counter
Count characters, words, and estimate tokens for LLM prompts. Useful for OpenAI, Claude, and other AI APIs.
LLM JSON Extractor
Extract JSON from LLM responses. Parse code blocks and clean malformed JSON from AI output.
MCP Tool Schema Generator
Generate Model Context Protocol (MCP) tool definitions. Create name, description, and inputSchema JSON for MCP servers.
その他 AI・LLM関連ツール
Prompt Token Counter
Count characters, words, and estimate tokens for LLM prompts. Useful for OpenAI, Claude, and other AI APIs.
LLM JSON Extractor
Extract JSON from LLM responses. Parse code blocks and clean malformed JSON from AI output.
MCP Tool Schema Generator
Generate Model Context Protocol (MCP) tool definitions. Create name, description, and inputSchema JSON for MCP servers.
MCP Config Formatter
Format and validate MCP server configuration (mcp.json). Pretty-print and check structure for Cursor, Claude, and other MCP clients.
llms.txt Generator
Generate llms.txt for your website. Creates AI-readable discovery file with name, summary, contact, and services. Spec 1.1.1 compatible.
Prompt Template Builder
Build prompts with {{variable}} placeholders. Fill in values and preview. For reusable AI prompts.
System Prompt Generator
Generate system prompts for LLMs. Role, task, constraints, output format. For ChatGPT, Claude, etc.
Few-Shot Prompt Builder
Build few-shot prompts with input-output examples. Structure examples for in-context learning.
よくある質問
- What is a system prompt?
- A system prompt is an initial instruction set given to an LLM to establish its persona, behavioral boundaries, expertise level, and response format.
- Why is structured prompt engineering important?
- Structuring prompts with clear Role, Task, Constraints, and Formatting prevents AI hallucinations and ensures predictable, production-ready outputs.
- Can I use these prompts for Custom GPTs and Claude Projects?
- Yes — the generated Markdown prompts are fully compatible with Custom GPT Instructions, Claude System Prompts, and LangChain/LlamaIndex agents.