llm-guard

A TypeScript library for validating and securing LLM prompts

DecliningOpen SourceLow lock-in

Pricing

Free tier

Flat rate

Adoption

Cooling

License

Open Source

Data freshness

Aging · Jun 8, 2026

Overview

What is llm-guard?

llm-guard is a TypeScript library designed to validate and secure Large Language Model (LLM) prompts, ensuring they are safe and appropriate before processing.

Key differentiator

llm-guard stands out as the only TypeScript library specifically designed for validating and securing prompts intended for Large Language Models, offering developers a robust solution to ensure their applications are both secure and compliant.

Capability profile

Capability Radar

Ease of StartEcosystemValueMaturityFlexibilityScale Ready

Honest assessment

Strengths & Weaknesses

↑ Strengths

Prompt validation and sanitizationmedium

Security checks for LLM inputsmedium

Customizable rules for prompt evaluationmedium

↓ Weaknesses

Limited language support beyond TypeScripthigh

The primary development is in TypeScript, and while there's a community-maintained Python SDK, it lacks the depth of official support.

Complex setup for non-TypeScript projectsmedium

Integrating llm-guard into projects that are not primarily built in TypeScript can be cumbersome due to a lack of comprehensive documentation and tooling outside of the TypeScript ecosystem.

Frequent breaking changes between versionshigh

Version updates from v0.1 to v0.2 required significant refactoring, indicating instability in API design which can disrupt ongoing projects.

Poor documentation for advanced use casesmedium

While basic usage is well-documented, detailed explanations and examples for more complex configurations or custom rule development are sparse.

Fit analysis

Who is it for?

✓ Best for

TypeScript developers building secure and compliant AI applications

Teams needing to validate user inputs before processing by LLMs

✕ Not a fit for

Projects requiring real-time validation in high-latency environments

Applications where prompt validation is not a critical concern

Cost structure

Pricing

Free Tier

Available

Open source — free to use

Starts at

$0

Model

Flat rate

Enterprise

None

Performance benchmarks

How Fast Is It?

Ecosystem

Relationships

Next step

Get Started with llm-guard

Step-by-step setup guide with code examples and common gotchas.

View Setup Guide →