100% Client-Side
Zero Proxy
Zero Logging
Local Privacy
How it works
Every HTTP request in httpclient.de is dispatched directly from your browser using the native fetch() API. There is no backend server proxy , no cloud relay, and no central logging. Your request payloads, headers, and API keys never leave your machine.
Your Browser Direct fetch()
TCP / TLS
Target API Direct response
Why do some requests fail?
Because requests are sent directly by your browser, web security standards are enforced by your browser sandbox:
1. Cross-Origin Resource Sharing (CORS)
Browsers block reading responses from different origins unless the server returns the Access-Control-Allow-Origin header. Custom headers and POST/PUT methods with JSON payloads also require the server to accept preflight OPTIONS requests.
2. Mixed Content Security
Modern browsers block plain http:// requests from secure https:// pages. APIs must support HTTPS when using the online client.
3. Forbidden Browser Headers
Headers like Host, Origin, User-Agent, Cookie, and Referer are restricted by the browser Fetch specification and cannot be overwritten via JavaScript.
Solutions & Workarounds
Run in Terminal (Bypass CORS)
Copy your request as a cURL command. Terminal cURL does not enforce browser origin sandboxes.
Copy request as cURL
Enable CORS on your Server
If you control the API, add these HTTP headers to permit browser requests:
Access-Control-Allow-Origin: * Access-Control-Allow-Methods: GET, POST, PUT, DELETE, OPTIONS Access-Control-Allow-Headers: *
Test with CORS-ready endpoints
Quickly load verified endpoints that support browser requests:
Nexus Status
Local Echo
Live Connection Diagnostic
Test if an endpoint can be reached directly from this browser right now:
Test connection