API Tester & HTTP Client
Test REST APIs and HTTP endpoints with this privacy-first API testing tool. Send GET, POST, PUT, PATCH, DELETE requests with custom headers, authentication, and request bodies. Generate code in 16+ programming languages including JavaScript, Python, PHP, Go, Ruby, and more. Perfect for API development, debugging, and integration testing.
Request Configuration
Response
No response yet
Configure your request and click "Send Request"
Privacy & Features
Privacy First: All requests are proxied through our secure API. No request data is logged or stored on our servers.
Request History: Your last 20 requests are saved locally in your browser using localStorage. Clear history anytime.
Full HTTP Support: Test any HTTP method (GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS) with custom headers, query parameters, and request bodies.
About API Tester & HTTP Client
The API Tester & HTTP Client is a comprehensive tool for testing REST APIs and HTTP endpoints directly in your browser. Send requests with any HTTP method, configure custom headers and query parameters, add authentication (Bearer token, API key), and inspect detailed responses including status codes, headers, body content, and performance metrics. Generate code snippets in 16+ programming languages including C#/.NET, Curl/Bash, Dart/Flutter, Go, Java, JavaScript, Kotlin, Node.js, Perl, PHP, PowerShell, Python, R, Ruby, Rust, and Swift. Features an intuitive auto-expanding interface for headers and parameters, multiple body formats (JSON, Plain Text, Raw Text, Form Data), and local request history. All requests are processed securely through our API proxy for maximum privacy.
Why use a API Tester & HTTP Client?
Testing APIs traditionally requires desktop applications like Postman or command-line tools like cURL. This browser-based API tester provides a lightweight, privacy-focused alternative with powerful code generation capabilities. Instantly generate production-ready HTTP request code in 16 programming languages - perfect for documentation, tutorials, or implementing API calls in your projects. View formatted JSON responses, measure response times, inspect headers, and maintain a local history of recent requests. The streamlined auto-expanding interface eliminates manual row management for headers and parameters. Supports all HTTP methods, multiple body formats (JSON, Plain Text, Raw Text, Form Data), and flexible authentication options without storing any sensitive data on external servers.
Who is it for?
Essential for frontend and backend developers testing API endpoints, DevOps engineers debugging microservices, QA testers validating API integrations, and API developers building and documenting REST APIs. Perfect for technical writers creating API documentation with code examples, developers learning new programming languages, teams sharing API integration code across multiple tech stacks, and anyone who needs a quick, privacy-first alternative to Postman with built-in code generation for 16+ languages.
How to use the tool
Enter your API endpoint URL in the URL field
Select the HTTP method (GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS)
Add custom headers in the Headers tab - rows expand automatically as you type
Configure query parameters in the Params tab with auto-expanding rows
Add request body in the Body tab (supports JSON, Plain Text, Raw Text, Form Data)
Set up authentication in the Auth tab (Bearer token or API key)
Click 'Send Request' to execute the API call
View response status, time, size, headers, and formatted body content
Click 'Generate Code' to create the request in your preferred language
Select from 16 programming languages and switch between them instantly
Copy generated code to implement the API call in your application
Access recent requests from history to replay or modify previous tests
Frequently Asked Questions
How do I test an API endpoint?
Configure the request: URL, HTTP method (GET, POST, PUT, DELETE, PATCH), headers (Content-Type, Authorization), body (JSON, form-data, raw), query parameters, basic auth. The tool sends the request via our backend (to bypass browser CORS limitations) and displays the response: status code, headers, body, timing. Useful for: ad-hoc API debugging, verifying endpoints before writing client code, sharing reproducible test cases with team. Faster than Postman for simple one-off tests.
Is the request sent through a server?
Yes — the backend acts as an HTTP client on your behalf. Reason: browser-based fetch is subject to CORS; many APIs you'd want to test don't return CORS headers for `*` origin. The backend isn't subject to CORS (server-to-server requests don't enforce it). We log only the target URL for rate-limiting; we don't store request bodies, auth tokens, or response bodies. **Caveat**: if your test request includes secrets (API keys, OAuth tokens, passwords), they transit our backend in cleartext (we use HTTPS, but they're decrypted to forward). For high-security testing, use curl locally or a desktop API client (Postman, Insomnia).
What's the difference between this and curl?
Functional equivalence; ergonomic difference. **curl**: command-line, scriptable, runs entirely locally (your machine is the HTTP client). **API Tester** (this tool): web UI, no setup, runs through our backend. Use this tool for ad-hoc one-off tests where convenience matters. Use curl when: (1) testing from a script, (2) sensitive credentials (don't transit through a third-party backend), (3) testing from a specific network context. Generate curl commands from your test inputs via [Curl Command Generator](/tools/curl-command-generator/).
What's the difference between this and Postman / Insomnia?
**Postman / Insomnia**: full-featured desktop apps with collections, environments, automated tests, team collaboration. Heavyweight but powerful. **API Tester** (this tool): lightweight web UI for one-off requests. Use Postman/Insomnia for: long-term API development, complex test suites, team collaboration, environment management. Use this tool for: quick debugging, sharing a one-off test, no-install scenarios. Many developers use both — desktop apps for ongoing work, web tools for fast triage.
How do I send authentication?
Common patterns supported. **Bearer token (OAuth/JWT)**: set Authorization header to `Bearer YOUR_TOKEN`. **Basic auth**: use the Basic Auth section (username + password — encoded as Base64 automatically). **API key in header**: add custom header like `X-API-Key: YOUR_KEY`. **API key in query string**: add to URL like `?api_key=YOUR_KEY`. **Cookies**: use cookie header for session-based auth. For OAuth flows requiring redirects, use Postman or write a script — multi-step auth flows aren't well-suited to single-request testers.
Does this support all HTTP methods?
Yes — GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS, and any custom method (some APIs use non-standard verbs). For each method, the appropriate body and headers are configurable. Some methods have conventions: GET typically has no body (some servers reject GETs with bodies); HEAD returns headers only (same as GET); OPTIONS is used for CORS preflight. For sending an OPTIONS preflight to verify CORS configuration, use [CORS Header Checker](/tools/cors-header-checker/) — purpose-built for that scenario.
How do I send a JSON body?
Set Content-Type header to `application/json` and the body to a valid JSON string: `{"key": "value"}`. Verify the JSON syntax with [JSON Formatter](/tools/json-formatter/) before sending — APIs reject malformed JSON. For complex bodies, draft in JSON Formatter, copy here. For multipart/form-data (file uploads), use a desktop client — most browser-based testers have limited file-upload support. For x-www-form-urlencoded, the tool handles form-style input.
Can I save and reuse test requests?
This tool is primarily for ad-hoc one-off requests; saved collections are a Postman/Insomnia feature. For reproducible testing: copy the request as a curl command (via [Curl Command Generator](/tools/curl-command-generator/)), then store the curl command in your team's documentation, README, or a shell script. For team-shared API tests, Postman Collections (public or private) or REST Client extensions for VS Code work well. For automated CI testing, write integration tests in your codebase with your test framework's HTTP-mocking tools.
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