---
title: "Guardrails AI Pricing, Features & Alternatives (2026)"
description: "Guardrails AI review: AI Guardrails & Agent Security tool — Free tier, plans, pros & cons, and the best Guardrails AI alternatives compared for startups in 2026."
source: https://appstackbuilder.com/tools/guardrails-ai
retrieved: 2026-10-17
---

![Guardrails AI logo](https://www.google.com/s2/favicons?domain=guardrailsai.com&sz=128)

[AI Guardrails & Agent Security](https://appstackbuilder.com/categories/ai-guardrails)Free tier

# Guardrails AI: Pricing, Features & Alternatives

Guardrails AI wraps model calls in a Guard made of validators: checks for toxic language, PII, competitor mentions, regex patterns, hallucination and more, each of which can block, fix or re-ask. It also forces structured output from a Pydantic model, using function calling where the model supports it. It runs in-process or as a REST server with an OpenAI-compatible endpoint. The framework is Apache-2.0 and downloaded over 250,000 times a month. Two 2026 changes matter: validators moved to ordinary PyPI packages and hosted remote inference ended on August 25, 2026, and the legal AI company Harvey acquired Guardrails AI on September 9, 2026\. Harvey has not said what happens to the open-source project, so watch its activity.

Category

AI Guardrails & Agent Security

Pricing

Free tier available

Free tier

Yes

Best for

AI Guardrails & Agent Security — guardrails, validation

[Visit Guardrails AI official site](https://www.guardrailsai.com)

## Guardrails AI Pricing Plans (2026)

| Plan               | Price           | Highlights                                                        |
| ------------------ | --------------- | ----------------------------------------------------------------- |
| Open sourcePopular | $0 (Apache-2.0) | Validators from PyPI · Structured output · REST server mode       |
| Pro                | Custom          | Hosted validation · Observability dashboards · Enterprise support |

Pricing summary: Free · paid plans by quote. Always confirm current pricing on the official site.

## Key Guardrails AI Features

* ✓Validators from PyPI
* ✓Structured output
* ✓REST server mode
* ✓Self-hosted

### ✓ Pros

* +Composable validators for many risks
* +Structured output from a Pydantic model
* +Apache-2.0, runs in-process

### ✗ Cons

* −Owned by Harvey since Sep 2026; roadmap uncertain
* −Hosted remote inference ended Aug 2026
* −Mostly checks text in and out, less about tool calls

## Best Guardrails AI Alternatives

[Compare all ](https://appstackbuilder.com/tool-alternatives/guardrails-ai)

[![Lakera Guard logo](https://www.google.com/s2/favicons?domain=lakera.ai&sz=128)Lakera GuardFree · paid plans by quote](https://appstackbuilder.com/tools/lakera-guard)[![NVIDIA NeMo Guardrails logo](https://www.google.com/s2/favicons?domain=nvidia.com&sz=128)NVIDIA NeMo GuardrailsFree](https://appstackbuilder.com/tools/nemo-guardrails)[![Amazon Bedrock Guardrails logo](https://www.google.com/s2/favicons?domain=aws.amazon.com&sz=128)Amazon Bedrock GuardrailsFrom $0.15/mo](https://appstackbuilder.com/tools/bedrock-guardrails)

## Guardrails AI Compared

[Guardrails AI vs Lakera Guard](https://appstackbuilder.com/compare/guardrails-ai-vs-lakera-guard)[Guardrails AI vs NVIDIA NeMo Guardrails](https://appstackbuilder.com/compare/guardrails-ai-vs-nemo-guardrails)[Guardrails AI vs Amazon Bedrock Guardrails](https://appstackbuilder.com/compare/bedrock-guardrails-vs-guardrails-ai)

[In-depth guideBest AI Guardrails 2026: NeMo Guardrails vs Guardrails AI vs Lakera Guard vs Bedrock GuardrailsPrompt injection, jailbreaks, leaked personal data and agents calling tools they should not. Two open-source guardrail frameworks and two hosted services compared on what they catch, where they sit, and what a million messages costs.](https://appstackbuilder.com/blog/best-ai-guardrails-tools-2026)

## Guardrails AI FAQ

What is Guardrails AI used for?⌄

Guardrails AI is a ai guardrails & agent security tool. Open-source (Apache-2.0) Python framework for validating LLM inputs and outputs: composable validators, structured output and a REST server. Acquired by Harvey in Sep 2026.

Is Guardrails AI free?⌄

Yes — Guardrails AI has a free tier you can start with, and paid plans for more usage and features.

How much does Guardrails AI cost?⌄

Guardrails AI is free to use, with usage-based pricing on some features.

What are the best Guardrails AI alternatives?⌄

Popular Guardrails AI alternatives include Lakera Guard, NVIDIA NeMo Guardrails, Amazon Bedrock Guardrails. Compare pricing and features on our Guardrails AI alternatives page.

## Not sure if Guardrails AI fits your stack?

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