Free Online API Tester
API Tester gives you a simple way to send HTTP requests to any endpoint and check the full response right in your browser. Just choose a method, type in the URL, set up your headers or body, and click Send. You'll see the status code, response time, body content, and every server header in the response panel. JSON responses are automatically formatted so they are easy to read. You can also test multipart endpoints by uploading files through form-data or binary body modes. Since every request fires directly from your browser, your data never passes through any third-party servers.
REST API Testing
Send GET, POST, PUT, PATCH, DELETE, HEAD, and OPTIONS requests with custom headers, query parameters, and body payloads.
File Upload Support
Upload files through multipart form-data or binary body mode to test file-receiving endpoints.
Response Inspector
View formatted response bodies, status codes, timing metrics, and all response headers in one panel.
Request History
Recent requests are tracked with method, URL, status, and response time for quick replays.
Multiple Body Formats
Choose from JSON, form-data, URL-encoded, raw text, or binary file body types for any endpoint.
Online API Tester for Developers and QA Teams
Testing APIs should be quick and straightforward. You can enter an endpoint, select your method, and have a request ready to go in seconds. As you type key-value pairs in the Params tab, the tool builds your query strings automatically. The Headers tab gives you complete control over auth tokens and content types, with checkboxes on every row so you can toggle headers on or off without deleting them.
Configure Request Bodies with Ease
You can choose from five different input formats in the Body tab. JSON mode gives you a clean text editor for structured payloads, while form-data mode is perfect for mixing text fields with file uploads. If you're working with traditional form submissions, use URL-encoded mode. You can also use Raw mode for plain text or Binary mode to send a file as the entire body. It only takes one click to switch formats, and your data stays put even when you change tabs.
Upload Files to Any Endpoint
Handling file uploads is easy thanks to our built-in support for multipart form-data. Just add a field, set it to File, and pick the file you want to upload. You can even include multiple files alongside your text fields in the same request. If your endpoint expects raw binary data, simply switch to binary mode and select your file. The upload goes directly from your browser to your server without any middleman.
Inspect and Debug API Responses
You get complete visibility into every response. The status bar shows you the HTTP status code, response time, and total payload size at a glance. You can click the Body tab to see your data or head over to the Headers tab for a full list of server headers. JSON responses are automatically pretty-printed with proper indentation, so you can easily read through nested structures without needing any extra tools.
Copy and Download Responses Instantly
When you need to share or save results, the Copy button puts the entire response body on your clipboard with a single click. The Download button saves the response as a file with the correct extension based on content type. Both options sit right in the response toolbar next to the status details.
Request History for Quick Replays
The History panel at the bottom of the left sidebar keeps track of your requests. You'll see the method, URL, and status code for each call you've made. If you want to re-run a previous request, just click it to reload the method and URL instantly. This history stays in your browser's memory for the current session and clears automatically when you close the tab.
Free API Tester with No Signup or Installation
Every feature is available the moment you land on this page. No accounts, extensions, or desktop downloads are needed to get started. All seven HTTP methods, file uploads, and response inspection tools work right out of the box. Since requests fire directly from your browser via the Fetch API, your tokens and payloads never touch our servers. Once you close the tab, all your session data is wiped from memory. This private, browser-based approach is ideal for testing internal APIs or endpoints that require sensitive credentials.
Runs Entirely in Your Browser
This tool uses client-side JavaScript to power every request you make. Because there are no proxy servers between your browser and the API endpoint, you get original headers and accurate response times. This also means you're free to test localhost or private network APIs that external testing services usually can't reach.
CORS Considerations
Since your requests start in the browser, the target API needs to return the right CORS headers for cross-origin calls. If you run into CORS errors, it usually means the server needs to be configured with Access-Control-Allow-Origin. Most modern frameworks have simple CORS middleware you can turn on while you're developing locally.
Related Developer Tools
These tools pair well with API testing workflows:
- JSON Formatter -- format, validate, minify, and transform JSON data
- JSON Validator -- check JSON syntax and get detailed error messages
- JWT Decoder -- decode and inspect JWT token headers, payloads, and signatures
- Base64 Encode -- encode data to Base64 for authorization headers and payloads
- Base64 Decoder -- decode Base64 strings from API responses
- URL Encoder -- percent-encode special characters in query strings and paths
- UUID Generator -- generate unique identifiers for test data and request IDs