Customizable runtime guardrails, evaluation, and red-teaming for enterprise generative and agentic AI
Runtime Enforcement & GuardrailsEU AI ActNIST AI RMF
Best LLM guardrail tools
9 tools · last reviewed 2026-07
Guardrails are the only category on this site that can actually stop a bad output reaching a user. They intercept prompts and responses in real time to block prompt injection, redact personal data, suppress toxic or off-topic content, and check answers against source material for grounding. The engineering trade-off is always the same: coverage against added latency.
How to choose
Measure added latency under your real traffic, confirm policies can be versioned and tested like code, and check whether the tool can run inside your own network boundary.
The shortlist
AI-native security platform guarding GenAI apps against prompt attacks and data loss
Runtime Enforcement & GuardrailsEU AI ActNIST AI RMF
Runtime security for enterprise GenAI usage, applications, and AI agents
Runtime Enforcement & GuardrailsNIST AI RMFEU AI ActGDPR
Full-lifecycle inference-layer security and guardrails for enterprise AI
Runtime Enforcement & GuardrailsNIST AI RMFEU AI Act
Open-source enterprise AI gateway with inline guardrails across 1,000+ models
Runtime Enforcement & GuardrailsOpen-source
Open-source framework for validating and correcting LLM inputs and outputs
Runtime Enforcement & GuardrailsOpen-source
Open-source toolkit for adding programmable rails to conversational LLM systems
Runtime Enforcement & GuardrailsOpen-source
Configurable safety, privacy and grounding safeguards for generative AI on AWS
Runtime Enforcement & Guardrails
Zero-trust runtime security and governance for enterprise AI agents
Runtime Enforcement & Guardrails
Ordering reflects how thoroughly each tool is publicly documented, not a quality score. Nobody pays to appear on this list. See our methodology.
AI Governance Tool Selection Kit
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