Chaos & Fault Injection

Arbitrary HTTP Status Code Injection

Force the API to return any standard HTTP error code using ?_status=... or the X-Simulate-Status header. Test React error boundaries, form validation errors, authorization fallbacks, and server outage alerts.

Interactive Status Code Runner

Select a target status code and click "Send" to inspect the generated RFC-compliant error payload:

4xx Client Error Simulations

5xx Server Error Simulations

Simulate HTTP 500

Forces server to return HTTP 500 with RFC-compliant error payload.

GET

response.json

{

// Click "Send" above to execute this request against the live server.

}

Supported HTTP Status Code Reference

Code	Standard Name	Typical Trigger Scenario	Recommended Frontend Action
400	Bad Request	Malformed JSON body or invalid query syntax.	Display inline form field validation errors.
401	Unauthorized	Missing or expired JWT bearer token.	Trigger token refresh or redirect to login.
403	Forbidden	User lacks required RBAC role permissions.	Show "Upgrade Plan" or permissions banner.
404	Not Found	Target resource ID does not exist in dataset.	Render 404 empty state page with navigation.
429	Too Many Requests	Rate limit window exceeded.	Read `Retry-After` and pause requests.
500	Internal Server Error	Uncaught backend exception or database failure.	Trigger React Error Boundary fallback view.
503	Service Unavailable	Scheduled maintenance or downstream outage.	Activate circuit breaker and retry with backoff.

Frontend Error Handling Recipes

Production patterns for catching simulated errors gracefully in modern web apps:

error.tsx

// React 19 / Next.js Error Boundary (error.tsx)

'use client';

import { useEffect } from 'react';

export default function ErrorBoundary({

error,

reset,

}: {

error: Error & { digest?: string; status?: number };

reset: () => void;

}) {

useEffect(() => {

console.error('Captured by Error Boundary:', error);

}, [error]);

return (

⚠️

</div>

<h2 className="text-xl font-bold text-slate-900">Something went wrong!</h2>

{error.message || 'An unexpected server error occurred.'}

</p>

<button

onClick={() => reset()}

className="px-4 py-2 bg-indigo-600 text-white text-sm font-semibold rounded-xl"

Try Again

</button>

</div>

);

}

Testing quota boundaries and rate limiting?

Simulate HTTP 429 Too Many Requests and parse compliant Retry-After headers.

View Rate-Limit Simulator

PreviousNetwork Latency Delay

NextRate-Limit Simulator