How do I use the API Tester?

Enter the API endpoint URL and select the HTTP method (GET, POST, PUT, DELETE, PATCH). Add request headers as key-value pairs and a JSON body for POST/PUT requests. Send the request and view the response status code, headers, and formatted body.

Is the API Tester free?

Yes, the API Tester is completely free. It runs entirely in your browser with no signup, no download, and no data sent to any server.

🔌

dev

API Tester

Send HTTP requests to APIs directly from your browser. Set method, headers, and body. View response status, headers, and JSON body.

api testerhttp clientrest api testerapi request builderpostman alternative

CORS-aware client

Simple API tester

Build and send browser-based requests with custom headers and a JSON body. This only works when the target API allows cross-origin requests from the browser.

Requests sent

Last status

—

Response time

—

Method Request URL

Request builder

Body enabled

Headers

Key / value pairs

JSON body

Optional

Response

Result inspector

Enter a URL, adjust the request, and click “Send request”.

Status

Waiting for a response…

Response headers

Returned by fetch()

Header	Value
Response headers will appear here after a successful request.

Response body

Pretty printed when possible

Response content will appear here.

How to use

How to Use the API Tester

1 Enter the API endpoint URL and select the HTTP method (GET, POST, PUT, DELETE, PATCH).
2 Add request headers as key-value pairs and a JSON body for POST/PUT requests.
3 Send the request and view the response status code, headers, and formatted body.

API testing is essential for development and debugging. This browser-based tool works with any API that has CORS enabled for cross-origin requests.

For APIs that restrict CORS, use this tool on the same domain or consider a proxy. The response viewer formats JSON automatically for readability.

More Dev tools

🔎 Regex Tester 🎨 CSS Gradient Generator 🖼️ CSS Box Shadow Generator 🔍 JSON Schema Validator 🔤 Font Pairing Generator 🌐 Favicon Generator 🔀 Flowchart Maker 📖 Regex Cheat Sheet View all 17 →

Related tools

🔎

dev

Regex Tester

Test regex patterns with live match highlighting, capture groups, flags, and reusable developer snippets.

regex tester

Use Tool →

🎨

dev

CSS Gradient Generator

Create beautiful CSS gradients with a visual editor. Choose linear or radial gradients, pick colors, adjust angles, and copy the CSS code instantly.

css gradient

Use Tool →

🖼️

dev

CSS Box Shadow Generator

Design perfect CSS box-shadow effects with a visual editor. Adjust offset, blur, spread, color, and inset to create shadows and copy ready-to-use CSS.

box shadow

Use Tool →

📊

converter