Free Online REST API Client — No Installation Required
The SUDTCore REST Client is a professional, browser-based REST API testing tool that works instantly — no downloads, no sign-ups, no desktop software. Whether you need to test a GET endpoint, debug a POST payload, or validate PUT/DELETE/PATCH operations, our client provides everything you need right in your browser.
Unlike Postman, Insomnia, or Thunder Client, SUDTCore requires zero installation — just open the URL and start testing. Your API requests are routed through our secure cloud proxy, so there are no CORS headaches and no browser restrictions.
Key Features
🚀 All HTTP Methods
GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS — full HTTP method support for complete API testing.
📋 JSON & XML Body
Switch between JSON, XML, and plain text body formats. Content-Type header updates automatically.
🔒 Secure CORS Proxy
Requests are routed through our secure cloud infrastructure, bypassing CORS restrictions. Your credentials and tokens are never stored.
💾 Save & Organize
Save requests into organizations and projects — just like Postman collections. Syncs across devices when signed in.
📊 Response Inspector
View formatted response body, status codes, timing, and headers in a clean, readable interface.
🌐 Zero Installation
Works entirely in your browser. No downloads, no extensions, no command-line tools. Just open and test.
Why Choose SUDTCore Over Postman?
- No installation — Postman requires downloading and installing a desktop app (500MB+)
- No account wall — Postman forces sign-up; SUDTCore works instantly for guests
- Instant sharing — Just share the URL to let teammates test APIs
- CORS bypass — Test any API without browser restrictions
- Lightweight — No Electron, no resource hogging
ENTERPRISE-GRADE SECURITY
All request bodies, tokens, and credentials are processed in-memory and never stored on our servers. API responses are never persisted — they exist only in your browser session. When you save a request, only the URL, method, and headers are stored — never the response data.
Frequently Asked Questions
Is this REST client really free?
Yes, 100% free. No sign-up required, no feature limits, no trial period.
Can I test APIs that require authentication?
Yes. Add Bearer tokens, API keys, or Basic Auth headers — they are sent through our proxy and never stored.
Does it support XML request bodies?
Yes! Use the body format toggle to switch between JSON, XML, and plain text. The Content-Type header updates automatically.
Can I save my API requests?
Yes. Organize requests into collections with organizations and projects. Sign in to sync across devices.