JSON Guardian

Stop AI Outputs From Breaking Your App

Validate, repair, and enforce JSON schemas on LLM outputs.
Sub-10ms response times. 99.8% uptime. Enterprise-grade.

7-day money-back guarantee on all paid plans

✓ Validate against JSON Schema
✓ Type coercion ("twenty" → 20)
✓ Auto-repair syntax errors
✓ Extract JSON from prose
✓ Complete streaming JSON
✓ Batch up to 100 items
<10ms
Average Latency
99.8%
Uptime SLA
$0
LLM Costs
3k+
Requests/sec

The Problem We Solve

Without JSON Guardian

  • AI returns string instead of JSON object
  • Missing required fields break your pipeline
  • Malformed JSON crashes production
  • Manual error handling eats dev time
  • Unpredictable LLM outputs cause outages

With JSON Guardian

  • Auto-repair common syntax errors
  • Enforce schemas with smart type coercion
  • Extract JSON from LLM prose/markdown
  • Complete streaming JSON in real-time
  • Batch process 100 items at once
  • Validate in under 10 milliseconds

Dead Simple Integration

One API call. Any language. Sub-10ms response.

// Validate LLM output against your schema
const response = await fetch('https://api.jsonguardian.com/api/v1/validate', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'X-API-Key': 'your-api-key'
  },
  body: JSON.stringify({
    schema: { type: 'object', required: ['name'] },
    data: llmOutput
  })
});

const { valid, parsed_data, errors } = await response.json();

Check JSON against a schema

Works with JavaScript, Python, Go, Rust, PHP, Ruby, and any language with HTTP.

Why Choose JSON Guardian?

Blazing Fast

Written in Rust. Sub-10ms latency. Handles 3,000+ requests per second.

Smart Repairs

Automatically fixes trailing commas, missing brackets, unquoted keys, and more.

Secure & Private

We don't log or store your JSON data. Processed in-memory and discarded.

Cost Effective

No LLM calls means pennies per million validations. Save 95%+ vs other solutions.

Real-Time Metrics

Track usage, monitor performance, and get alerts via our dashboard.

Global Edge

Deployed worldwide for low-latency responses wherever your users are.

Simple, Transparent Pricing

Free

$0/mo
  • 10,000 requests/month
  • All core features
  • Email support
  • No credit card required
  • Community support
MOST POPULAR

Starter

$9/mo
  • 100,000 requests/month
  • All features
  • Priority email support
  • 99.9% uptime SLA
  • Usage analytics

Pro

$29/mo
  • 1,000,000 requests/month
  • All features
  • Priority support (24hr)
  • 99.9% uptime SLA
  • Advanced analytics

All prices in USD. Cancel anytime. 7-day money-back guarantee. Upgrade from Dashboard → Billing after signup.

Frequently Asked Questions

Absolutely. We don't log or store your JSON data. All requests are processed in-memory and immediately discarded. We only track usage counts for billing purposes. Your data never touches our database.

Ready to Stop AI From Breaking Your App?

Join developers building reliable AI applications with JSON Guardian.

Questions? Email us at support@jsonguardian.com