API Request Dashboard: Test GET & POST Requests Online
Enter a URL, choose GET or POST, add JSON headers and a body, and read the formatted response instantly. Every request is saved to a local history. Free, no sign-up, no server in between.
Headers are a JSON object. Leave empty to send none.
Sent with POST. JSON bodies get a Content-Type header automatically.
Enter a URL and press Send, or press Ctrl+Enter (Cmd+Enter on Mac). The target server must allow cross-origin requests from this site.
Try an example
No response yet.
Browsers only expose response headers that the server lists in Access-Control-Expose-Headers, plus a short safe list.
How to use this tool
1. Enter the URL and method
Paste the endpoint into the address bar and pick GET to read data or POST to send data. If you leave out https://, it is added for you.
2. Add headers
Open the Headers tab and write a JSON object such as {"Accept": "application/json"}. Invalid JSON is flagged as you type, and Format JSON tidies it up.
3. Add a body for POST
The Body tab is editable for POST requests. A JSON body is sent with Content-Type: application/json unless you set that header yourself.
4. Send and read the response
Press Send or Ctrl+Enter. You get the status, time and size, plus a formatted, color-coded body. Switch to the Headers tab to see response headers, or use Copy to grab the body.
5. Reuse past requests
Every request is added to the History list on the left. Select one to reload its method, URL, headers and body. Remove single entries or clear the list at any time.
How it works
This dashboard uses the browser’s built-in fetch() API. When you press Send, your browser calls the API directly. There is no proxy and no DeveloperJar server in the middle, so your URLs, tokens and responses are never sent to us.
Because the request comes from your browser, the browser’s CORS rules apply. The API has to answer with an Access-Control-Allow-Origin header that permits this site, or the browser blocks you from reading the response. Many public APIs allow this. Private or internal APIs often do not, and this tool shows a clear message when that happens.
Your history lives in localStorage, which is private to this browser on this device. Header values for Authorization, Cookie and API-key style headers are replaced with a placeholder before saving, but request bodies are stored as typed, so avoid putting secrets in them.
Why a request fails
The browser reports most network problems the same way, so use this table to narrow it down.
| What you see | Likely cause | What to try |
|---|---|---|
| Request failed before a response | The server doesn’t allow cross-origin requests (CORS), or the address is wrong. | Check the URL, then add CORS headers on the server or test from the same origin. |
| Blocked http:// request | This page is served over HTTPS, and browsers block plain HTTP calls. http://localhost is allowed. | Use an https:// URL. |
| 401 or 403 | The API needs credentials or your token has no access. | Add an Authorization header in the Headers tab. |
| 404 | The path doesn’t exist on that server. | Check the path, version prefix and trailing slash. |
| 415 | The server doesn’t accept the body’s content type. | Set Content-Type explicitly in the Headers tab. |
| 429 | You hit a rate limit. | Wait and retry, and look for a Retry-After response header. |
| Timed out after 30 seconds | The server is slow or unreachable. | Check that it is running, then send the request again. |
Frequently asked questions
What is an API request dashboard?
It is a browser-based tool for sending HTTP requests to an API and inspecting the response. You enter a URL, choose GET or POST, add headers and a body, and see the status, timing, headers and formatted body without writing any code.
Does my request go through DeveloperJar servers?
No. The request is made by your browser with the built-in fetch() API and goes straight to the API you entered. There is no proxy in between, and DeveloperJar never sees your URLs, tokens or responses.
Why do I get a failed request with no status code?
Usually the API doesn't allow cross-origin requests from this site (CORS), the address is wrong, or you're offline. Browsers hide the exact reason from page scripts, so check the console. Calling the same API from a server or a tool like curl is not affected by CORS.
Where is my request history stored?
In your browser's localStorage, on this device only. The last 50 requests are kept. Clearing site data in your browser, or using Clear all in the History panel, removes it. Values of Authorization, Cookie and API-key headers are replaced with a placeholder before saving.
Can I send other methods like PUT, PATCH or DELETE?
This version supports GET and POST. Those cover most quick checks, and keeping the form simple makes the tool faster to use.
Is it a replacement for Postman?
It is a lightweight alternative for quick requests: no install, no account and nothing to configure. For collections, environments, scripts and team sharing, a full API client is a better fit.