API Tester
Send HTTP requests and test API endpoints
The API Tester sends an HTTP request through Tool-web's server proxy and shows the returned status, response time, headers, and body. It is useful for quick endpoint debugging when you need a lightweight request builder in the browser rather than a full API client. You control the method, URL, headers, and raw body directly.
Your request URL, headers, and optional body are sent to Tool-web's server over HTTPS so the target API can be called safely.
How to Use
- Enter the request URL and choose the HTTP method
- Add any headers you need and a request body for non-GET and non-HEAD methods
- Click "Send Request"
- Inspect the response status, timing, body, and headers tabs
Features
- GET, POST, PUT, PATCH, DELETE, HEAD, and OPTIONS methods
- Editable custom headers with enable/disable toggles
- Raw request body editor for methods that send a body
- Response body and headers tabs with status, timing, and size summary
- Reset action for clearing the request quickly
Tips for getting API Tester right
- Check the status code before reading the body — 2xx means success, 4xx/5xx mean the server rejected the request
- Set Content-Type to application/json when sending a JSON body
- Include the Authorization header for endpoints that require it
- Test error paths as well as happy paths to confirm your client handles failures
Worked example: debug a 401 on a JSON POST
Set the method to POST, paste the endpoint URL, add `Content-Type: application/json` and `Authorization: Bearer ...`, then send a small test payload. If the response comes back 401, you can switch to the Headers tab immediately to confirm what the endpoint returned while keeping the original request visible above.
What this tool sends for you
- The browser sends one POST request to Tool-web's `/api/api-tester` endpoint
- Tool-web's server forwards the target method, URL, headers, and optional body
- The UI then shows the returned status, headers, body, response time, and body size
- There is no built-in request history, collection manager, or auth helper wizard
Real-World Use Cases
- Testing REST API endpoints during development
- Debugging request headers and response payloads
- Checking whether an endpoint accepts a JSON body
- Reproducing a failing API call without opening a desktop client
- Inspecting raw response headers while tuning an integration
Best Practices
- Start with the simplest possible request before adding optional headers and body fields
- Set Content-Type explicitly when sending JSON or other structured payloads
- Check both the status line and the headers tab before assuming the body tells the whole story
- Use small test payloads first when you are not sure what the endpoint expects
- Avoid pasting long-lived production secrets unless you are comfortable routing them through this proxy
Common Mistakes to Avoid
- Not setting the correct Content-Type header for request bodies
- Forgetting to include authentication tokens in protected endpoints
- Using the wrong HTTP method (GET vs POST vs PUT)
- Not checking response status codes before processing data
- Sending large payloads without checking server limits
Troubleshooting
- For 401 or 403 responses, verify the Authorization header and token freshness first
- If the response body is empty, confirm the endpoint really returns content for that method
- For 415 or 400 errors, check that Content-Type matches the body format you pasted
- If the request times out, simplify the payload or confirm the upstream API is reachable
- If the result looks strange, double-check that the request URL includes the full path and query string you intended
Frequently Asked Questions
What HTTP methods are supported?
Can I send JSON request bodies?
Does it handle authentication?
Privacy & Security
Request URLs, headers, and optional bodies are sent to Tool-web's server over HTTPS so the target API can be called safely. Tool-web rate-limits these requests and does not intentionally store the submitted request data in the application, but the destination API may log what you send. Avoid pasting production secrets unless you are comfortable sending them through this proxy.
Tips & Best Practices
- Check the status code before reading the body — 2xx means success, 4xx/5xx mean the server rejected the request
- Set Content-Type to application/json when sending a JSON body
- Include the Authorization header for endpoints that require it
- Test error paths as well as happy paths to confirm your client handles failures
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