What is an Online API Tester & Studio?

An API tester is a utility allowing developers and QA engineers to send HTTP request configurations (GET, POST, PUT, DELETE, PATCH, etc.) to target backend servers and verify response payloads, headers, status codes, and connection latency metrics directly from the browser window.

How do I bypass CORS blocking when testing public APIs in the browser?

Simply check the "CORS Relay Proxy" toggle located right below the URL bar. This routes the request through a secure relay, enabling you to test third-party endpoints that lack browser wildcard CORS headers.

How does the JWT Token Inspector work?

The studio automatically detects standard JSON Web Tokens (JWT) in Bearer auth headers or response payloads, instantly decoding the Header, Claims (exp, iat, sub, roles), and live expiration validity.

Can I export requests to Postman or code snippets?

Yes! You can export your entire multi-tab session into a standard Postman Collection v2.1 JSON file, or copy ready-to-run code snippets in cURL, JavaScript (Fetch/Axios), Python (Requests), Go, PHP, C#, Swift, Rust, and Dart.

Free Online API Tester — REST API Client, HTTP Request Builder & Studio

Send HTTP requests (GET, POST, PUT, DELETE), inspect JSON tables and decoded JWTs, bypass CORS with relay proxy, run test assertions, and export code snippets.

⚡ Interactive Calculation Engine Active

Please enable JavaScript in your browser to run live computations, 2D envelope diagrams, and export PDF reports.

How to Use REST API Client & HTTP Request Studio

Create or switch between multi-tab request sessions and select your HTTP method (GET, POST, PUT, DELETE, PATCH).
Enter the target endpoint or use environment variables (e.g. {{baseUrl}}).
Configure Headers, Query Params, Bearer/Basic/API-Key Auth (with live JWT decoding), and JSON/GraphQL/Form payloads.
Click Send (or press Ctrl + Enter) and inspect response metrics, interactive JSON Data Tables, decoded JWT claims, and security headers.
Run automated assertion tests, export Postman Collection v2.1 JSON, and generate code snippets in 10+ languages.

What is a REST API Client & HTTP Request Studio?

An HTTP Request Studio allows developers to construct backend requests by choosing HTTP verbs (GET, POST, PUT, DELETE, etc.), mapping headers, appending query parameters, and embedding body payloads. This is essential for testing microservices, GraphQL endpoints, and third-party APIs during development.

Browser Security Restrictions & CORS Relay Handling

Browser-based clients are subject to CORS restrictions. If the target API doesn't return the header `Access-Control-Allow-Origin: *` or explicitly permit the origin, the browser will restrict access. Toolique provides an integrated CORS Relay Proxy toggle as well as 1-click cURL export to test any endpoint seamlessly.

Automating Verification checks with Assertions Lab

Assertions permit you to declare checks (e.g. status code equals 200, response latency under 1000ms, JSON property matching) that run automatically upon response arrival, accelerating regression testing and QA sanity validations.

Converting Responses to JSON Tables and Schema Models

Quickly convert raw JSON array responses into interactive searchable Data Tables, and generate formal JSON Schema specifications (Draft-07), OpenAPI 3.0 definitions, and Markdown documentation.

Frequently Asked Questions

What is an Online API Tester & Studio?: An API tester is a utility allowing developers and QA engineers to send HTTP request configurations (GET, POST, PUT, DELETE, PATCH, etc.) to target backend servers and verify response payloads, headers, status codes, and connection latency metrics directly from the browser window.
How do I bypass CORS blocking when testing public APIs in the browser?: Simply check the "CORS Relay Proxy" toggle located right below the URL bar. This routes the request through a secure relay, enabling you to test third-party endpoints that lack browser wildcard CORS headers.
How does the JWT Token Inspector work?: The studio automatically detects standard JSON Web Tokens (JWT) in Bearer auth headers or response payloads, instantly decoding the Header, Claims (exp, iat, sub, roles), and live expiration validity.
Can I export requests to Postman or code snippets?: Yes! You can export your entire multi-tab session into a standard Postman Collection v2.1 JSON file, or copy ready-to-run code snippets in cURL, JavaScript (Fetch/Axios), Python (Requests), Go, PHP, C#, Swift, Rust, and Dart.