AI & Prompt Tools · Free tool
Prompt Injection Detector
Scan text for prompt-injection patterns like role hijacks and hidden unicode instantly. Free online detector tool with no sign-up, browser-only.
Advertisement
What it does
Pre-filter for untrusted text before you pipe it into an LLM. Scans for known injection patterns: override attempts (“ignore previous”), role hijacks, system-prompt forgery, fake admin/dev modes, hidden zero-width and bidi unicode characters, and more.
Caveat: this is a fast first line of defense, not a complete solution. Real defense layers structured tool-use schemas, explicit confirmation for destructive actions, and treating all tool outputs as untrusted by default.
Embed this tool on your siteShow snippetHide
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/prompt-injection-detector" width="100%" height="720" frameborder="0" loading="lazy" title="Prompt Injection Detector" style="border:1px solid #e2e8f0;border-radius:12px;max-width:720px;"></iframe>How to use it
- Paste any text headed for an LLM.
- Read the verdict.
- Treat any high-risk match as a refusal trigger upstream.
Advertisement
Learn more
Guides about this topic
- AI & LLMs · GuideHow to Set Up an AI AgentNavigate a plain-English decision tree to pick the right AI agent stack for 2026. Free, instant online walkthrough, no sign-up.
- AI & LLMs · GuideHow to Use ChatGPT Agent ModeWhere /agent is available (Plus, Pro, Team — not Free), the 8 tasks it actually does well, and the 5 it can't. Plus the briefing template that works.
- AI & LLMs · GuideHow to Build an Agent with the OpenAI Agents SDKBuild a working Python agent with OpenAI's Agents SDK — tools, handoffs, guardrails, and the model-native sandbox harness. Free guide, no sign-up needed.
- AI & LLMs · GuideHow to Build an Agent with the Claude Agent SDKBuild an agent with the Claude Agent SDK — install, write custom tools, add hooks, compose sub-agents on the harness powering Claude Code. Free guide.
- AI & LLMs · GuideHow to Set Up Claude CodeConfigure Claude Code with permissions, MCP servers, and sub-agents for a full working setup. Free browser-only guide, no sign-up.
- AI & LLMs · GuideHow to Set Up Cursor AI IDEOptimize Cursor AI IDE modes, .cursorrules, and model picks to avoid credit-pricing traps. Free, instant configuration guide, no sign-up.
Explore more ai & prompt tools tools
- AI Image Prompt HelperBuild effective image prompts: pick style, lighting, camera, aspect ratio, extras. Outputs prompt + negative prompt for Midjourney, DALL-E, FLUX, SD 3.5.
- Open-Source LLM TrackerLive tracker of 15 open-weight LLMs: Llama 3.3/4, Qwen 3.5, DeepSeek V3.2/R1, Kimi K2, Mistral Large 3, Gemma 3, Phi-4, SmolLM3. Filter by license.
- AI Transcription Tools Compared9 transcription tools compared: Otter, Whisper API, Deepgram Nova-3, AssemblyAI, Rev, Sonix, Granola, Zoom AI, MacWhisper. Accuracy, languages, pricing.
- AI Data Residency CheckerFind AI providers compliant with your region (US, EU, UK, APAC, Canada) and certifications (SOC 2, HIPAA). Includes Bedrock, Azure, Mistral, self-host.
- AI Context Window PlannerPlan your prompt budget across system + docs + history + output + buffer. See which AI models (Claude, GPT, Gemini, DeepSeek, Kimi) fit your needs.
- AI Agent Platforms Compared10 agentic AI platforms compared: ChatGPT Operator/Atlas, Claude Computer Use, Devin, Manus, Replit Agent, Cursor Background Agents, Bolt.new, v0, Lovable.