API Response Visualizer
Enter any public API URL to fetch and inspect the full HTTP response — status code, response headers, timing, body size, and formatted JSON output. A lightweight alternative to Postman for quick API exploration in your browser.
CORS note
This tool makes requests directly from your browser. APIs must allow cross-origin requests (CORS) to respond successfully. Most public APIs listed on this site support CORS — try the sample URLs above to get started. Private or server-side-only APIs will fail with a CORS error.
What you can inspect
Status code
See the HTTP status code and status text for any request
Response headers
Inspect all response headers including Content-Type, Cache-Control, CORS headers
Timing
Measure round-trip response time in milliseconds
Body size
View response body size in bytes and KB
JSON formatting
Response body is pretty-printed and syntax-highlighted
Sample URLs
Preloaded example public API URLs to get started quickly
How to use
- 1
Enter URL
Type or paste any public API endpoint URL into the input field. Try one of the sample URLs to get started.
- 2
Send request
Click "Send" to make a GET request from your browser to the API endpoint.
- 3
Inspect response
View the HTTP status code, response time, and body size at a glance.
- 4
Explore tabs
Switch between Body (formatted JSON), Headers (all response headers), and Raw views.
Frequently asked questions
What APIs can I test with this tool?
Any publicly accessible REST API that supports CORS (Cross-Origin Resource Sharing) from browser requests. This includes most public API directories, weather APIs, cryptocurrency price APIs, and government open data endpoints. APIs that require API keys or block browser requests will return errors.
Is this tool similar to Postman?
This is a lightweight browser-based inspector for quick GET request testing — useful for exploring public APIs and checking responses. Postman and Insomnia are full-featured API clients that support all HTTP methods, authentication, environments, collections, and automated tests. Use this tool for quick checks; use Postman for complex workflows.
Why is the response body empty?
Some endpoints return 204 No Content by design. Others may return a response that the browser blocked due to CORS or other policies. Check the status code and headers tab for clues. If the API requires authentication, a 401 or 403 response will typically have an empty or error body.
How do I read API response headers?
Response headers contain metadata about the response. Key headers to look for: Content-Type (the format of the body, e.g., application/json), Cache-Control (caching directives), X-Rate-Limit-* (rate limiting info), Access-Control-Allow-Origin (CORS permission), and ETag (content version for caching).