Documentation → general
Getting Started: Your First Successful Request
Your first goal is a successful request using your own API key. Then verify the same request from your deployed app.
1. Get your key and register your app domain
Create a free account or sign in. In Manage domains, register the website making the browser request, such as my-app.example.com, rather than the API or image host you want to fetch. Check the normalized domain preview before saving. Localhost is available for local browser development.
Free includes 10,000 browser requests and 1 GB per month. Server-side requests require a paid plan. Compare plans and rate limits before using advanced features.
2. Put your key in the request
Replace YOUR_API_KEY below with the key from your account. Run the example in your browser app. URLSearchParams encodes the complete target URL, including any query string.
const params = new URLSearchParams({
key: 'YOUR_API_KEY',
url: 'https://jsonplaceholder.typicode.com/users/1',
});
const response = await fetch('https://corsproxy.io/?' + params);
if (!response.ok) {
throw new Error('HTTP ' + response.status + ': ' + await response.text());
}
const data = await response.json();
console.log(data);Expect HTTP 200 and a JSON object containing id: 1. Your CORSPROXY key belongs in the key query parameter. An upstream API’s authorization token is separate; never put a private upstream credential in browser code.
The playground prepares your account key, runs the request, and explains errors. Shared demo-key success does not verify your account setup.
3. Diagnose errors and retry
| What you see | What to do next |
|---|---|
| Missing or invalid API key | Copy your account key again and check the key parameter. |
| Origin or Referer not registered | Register the browser app’s domain, check the normalized preview, and retry from that app. |
| Plan or content restriction | Start with the JSON example above. Conversion, extraction, and caching controls require Production. |
| HTTP 429 | Inspect the body and Retry-After; the limit may come from CORSPROXY or the target. Wait before retrying. |
| HTTP 403 or another target error | Inspect the body and upstream authentication. The status alone does not identify the cause. |
| Network error or timeout | Check the target URL and connection. Open the browser Network panel and use the playground’s diagnosis. |
Keep your target and key in place while correcting the problem. See troubleshooting for more detail.
4. Verify production usage
Deploy the same keyed request to your registered domain and confirm both a successful HTTP response and the expected data in your app. A playground or localhost success does not validate the deployed origin. Check your dashboard usage after traffic arrives; analytics can be delayed or sampled.
Continue using the integration over multiple days. Choose a paid plan when your traffic, server-side use, or features require it. Hobby starts at $5/month with 300 requests/minute; Production is $29/month with 3,000 requests/minute. Pricing lists all allowances and fair-use terms.