LochBot
Free browser-based prompt injection vulnerability checker. Analyzes LLM system prompts against 31 attack patterns (jailbreaks, role override, data exfiltration) and returns a security score with remediation guidance. No signup, runs client-side.
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What is LochBot?
LochBot is a free prompt injection vulnerability checker that analyzes chatbot system prompts for security weaknesses. The tool tests your prompt against 31 known injection attack patterns organized across 7 categories: direct injection, context manipulation, delimiter attacks, data extraction, role play jailbreaks, encoding attacks, and prompt leaking. Each attack pattern is documented in security research from organizations like OWASP and validated against real-world prompt injection attempts.
When you paste your system prompt and click
LochBot pricing
Pricing model: Freemium
LochBot is completely free to use with no paid tiers, subscriptions, or hidden costs. The tool is 100% free forever with no usage limits, no premium features, and no account required. All 31 attack patterns, all 7 categories, security scoring, fix suggestions, and JSON export are included free. There are no upgrades available since the entire tool is free.
LochBot pros
- Completely free to use with no paid plans or subscriptions
- 100% client-side processing — your prompt never leaves your browser
- Tests against 31 documented attack patterns across 7 categories
- Provides 0-100 security score with A-F letter grade
- Scores each vulnerability by severity (critical, high, medium, low)
- Gives specific fix suggestions for every detected vulnerability
- No API calls, no server processing, no data collection
- No account or signup required to use the tool
- JSON export for compliance reporting and documentation
- Uses OWASP-validated attack patterns from security research
- Instant analysis with immediate results
- Comprehensive coverage from direct injection to encoding attacks
- Open source code available on GitHub for inspection
- No analytics tracking of prompt content
- Works entirely in browser with no installation needed
LochBot cons
- Only analyzes prompt structure, not actual model behavior
- Cannot replace red-team testing against deployed models
- No API integration for automated CI/CD pipelines
- No team collaboration or shared project features
- No historical tracking of prompt security over time
- Browser-based only — no desktop or mobile app
- Limited to prompt injection, no other LLM security checks
- No custom attack pattern creation or upload capability
Frequently asked questions about LochBot
What is prompt injection?
Prompt injection is a security vulnerability where an attacker crafts input that manipulates an AI chatbot into ignoring its system prompt instructions. Attacks include direct instruction overrides, role play jailbreaks, and data extraction attempts. It is the number one security risk for LLM-powered applications according to the OWASP Top 10 for LLMs.
How do I test my chatbot for prompt injection?
Paste your chatbot's system prompt into LochBot. The prompt injection checker analyzes your prompt against 31 attack types across 7 categories. You get a 0-100 security score, letter grade, and specific fix suggestions for each vulnerability detected.
What are the most common prompt injection attacks?
The most common attacks are direct instruction override, system prompt extraction, DAN jailbreaks, delimiter escape attacks, and context manipulation. These five prompt injection patterns cover roughly 80% of injection attempts seen in the wild.
How do I make my system prompt more secure?
Use unique XML delimiters, explicitly forbid instruction disclosure with multiple verb variants, block role changes by name, include few-shot refusal examples, and declare your instructions as immutable. LochBot tests for all of these defensive patterns.
Does this tool send my data anywhere?
No. LochBot is 100% client-side. Your system prompt never leaves your browser. All analysis runs using local pattern matching in JavaScript with no API calls, no server processing, and no data collection.
What is the difference between LochBot and red-team testing?
LochBot analyzes your prompt's defensive structure using pattern matching. Red-team testing sends actual attack inputs to your deployed model to see if it resists them. LochBot is a first-pass structural analysis; red-team testing is a behavioral test against a running model. Both are needed for comprehensive prompt security.
Can I export the vulnerability report?
Yes. After analyzing your system prompt, click the Export JSON button to download a complete vulnerability report. The export includes your security score, grade, and detailed results for each of the 31 attack patterns tested.
What are the 7 attack categories LochBot tests?
LochBot tests across 7 categories: direct injection, context manipulation, delimiter attacks, data extraction, role play jailbreaks, encoding attacks, and prompt leaking. Each category contains multiple specific attack patterns validated against real-world attempts.
Who should use LochBot?
LochBot is used by security engineers auditing chatbot deployments, developers building LLM-powered applications, and product teams launching customer-facing AI features. It's also used by organizations in regulated industries for compliance documentation and by AI security researchers studying prompt injection defense effectiveness.
Is LochBot open source?
Yes, the source code is available on GitHub for inspection. You can verify the client-side-only behavior by checking your browser's network tab during analysis to confirm no data is sent to any server.