LLM Prompt Injection Shield — Armor Your System Prompt

The Prompt Injection Shield wraps your core system prompt with defensive boundaries and clear instructions so the AI model is less likely to follow injected or jailbreak prompts from users. It adds specific prefixes and suffixes to define a single “system instruction” block.

Why Use This Tool?

• Reduce jailbreak risk: Makes it significantly harder for users to execute “ignore previous instructions” attacks.
• Model-specific formatting: Easily switch between Markdown-style delimiters (great for ChatGPT/Gemini) and XML tags (highly recommended for Anthropic’s Claude).
• Clear boundaries: Firmly delimits where your system rules end and user content begins.
• Copy-paste ready: Zero friction. Just paste your rules, select your model, and copy the armored result directly into your API.

Key Features

• Format Toggle: Switch between Standard (Markdown) and Claude (XML) protection wrappers in one click.
• Refusal Phrase: Automatically embeds a fallback phrase so the model knows exactly how to respond when an injection is detected.
• Live Update: The output generates instantly as you type or change dropdown settings.
• One-Click Copy: Copies the fully armored prompt straight to your clipboard.

How it Works

The tool simply prepends and appends proven, fixed defensive text around your core prompt. The prefix strongly states that the following block is the absolute only system instruction. The suffix reinforces this boundary and provides a default refusal line. It operates entirely in your browser with zero API calls.

Try the Prompt Injection Shield

Select your target LLM format, paste your core system prompt above, and copy the armored version below to use in your application. Note: no defense is 100% perfect, so always pair this with other safeguards like input filtering.