API Response Checker
Send HTTP requests to any API endpoint and inspect the response — status code, response time, size, headers, and body. All from your browser.
API Response Checker
Headers
Enter a URL and click Send Request to see results.
Note: The browser enforces CORS. Public APIs that allow cross-origin requests will work. APIs without CORS headers will fail with a network error — this is a browser limitation, not a bug.
What this tool checks
API Response Checker sends an HTTP request to any publicly reachable endpoint and returns the status code, total response time (DNS + TCP + TLS + server processing), payload size in bytes, response headers, and the response body. It supports GET, POST, PUT, PATCH, DELETE, and HEAD methods.
Why use it online?
Testing APIs from the browser avoids context switching between curl, Postman, and your code editor. It is ideal for quick health checks, verifying CORS headers, debugging integration issues, and sharing results with teammates during code review.
CORS and cross-origin requests
Browsers enforce Cross-Origin Resource Sharing (CORS) for security. An API must explicitly allow your origin via Access-Control-Allow-Origin headers. Public APIs with permissive CORS (e.g. JSONPlaceholder, PokeAPI) will work. Most production APIs (Stripe, GitHub, etc.) restrict CORS to their own origins and will return a network error from this tool — use a proxy, server-side client, or browser extension to test those.
Tips for best results
Start with a GET request to a public API to verify the tool works. Use custom headers to pass API keys for services that allow browser-based access. Format JSON bodies with the JSON Formatter tool before pasting. Always interpret response times in context — a 200 OK under load may be slower than a cached 304 from a CDN.
How to use
- Paste the API endpoint URL and select the HTTP method.
- Add any custom headers (e.g. Authorization, Content-Type) if needed.
- Add a JSON request body for POST, PUT, or PATCH requests.
- Click Send Request and wait for the response.
- Review the status code, response time, size, headers, and body below.
- Use Copy buttons to paste any value into your editor, ticket, or chat.
在线工具与终端对比
| 终端 / CLI | 本工具 |
|---|---|
| Write curl commands with flags and escaped headers | Paste URL, pick method, add headers visually |
| Pipe through jq or sed to extract fields | Status, timing, size, headers, and body shown in one view |
| Guess at timing with time curl ... | Copy any field with one click |
All requests are sent directly from your browser to the target API — no data passes through any Skybin server. Be careful with sensitive API keys in headers: they will appear in the request the browser sends.
常见问题
- Why do some APIs return a network error?
- The target API likely does not have CORS headers that allow requests from your origin (skybin.io). This is a browser security feature, not a tool bug. For APIs that restrict CORS, use a server-side client or a CORS proxy.
- Can I send API keys or secrets?
- Yes, via custom headers — but be aware that anything you enter here goes directly from your browser to the target API. Avoid entering highly sensitive credentials into browser-based tools. This tool is designed for debugging and development, not production secret management.
- Is this tool free?
- Yes. All Skybin developer tools are free with no account, API key, or usage limits.
- What does response time include?
- Response time is measured from the moment the browser starts the request to when the full response body is received. This includes DNS lookup, TCP handshake, TLS negotiation, server processing, and network transfer.
- Does this tool cache responses?
- No. Every request is sent fresh to the target API. Browser caching depends on the target API's Cache-Control headers.
- Can I use this for SOAP or gRPC APIs?
- This tool works with any HTTP endpoint that responds to standard REST methods. SOAP over HTTP works. gRPC (HTTP/2 with protobuf) will return a binary response that cannot be meaningfully displayed here.