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Home / Developer & Engineering Suite / WebSocket & SSE Realtime Tester
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WebSocket & SSE Realtime Tester

Connect to wss:// and SSE endpoints and log messages with latency.

🔒 Runs locally · no upload0 uses
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WebSocket & SSE Realtime Tester: free online, no upload

WebSocket & SSE Realtime Tester is a free online tool for developers, DevOps engineers and students learning to code. Connect to wss:// and SSE endpoints and log messages with latency. It works instantly in any modern browser on Windows, Mac, Android and iPhone, with no installation, no sign-up and no limits. Your code, data and API payloads are processed on your own device using the open-source websockets/ws library, so nothing is uploaded and your privacy is protected. People use it when they search for websocket, sse, tester.

How to use WebSocket & SSE Realtime Tester

  1. Open the tool: Open WebSocket & SSE Realtime Tester on this page. It loads in a few seconds and runs inside your browser tab.
  2. Add your input: Add your code, data and API payloads or type the values. Nothing is uploaded to any server.
  3. Adjust and preview: Change the options and check the live preview until the result is exactly what you need.
  4. Download or copy: Download the result or copy it. You can repeat it as many times as you like, free.

Key features

  • Connect to wss:// and SSE endpoints and log messages with latency
  • 100% free and unlimited, with no watermark, no credits and no paid plan
  • Runs locally in your browser for privacy and speed
  • Works on mobile, tablet and desktop
  • Download, print or copy results instantly

Popular uses

  • Speed up daily development work
  • Debug and inspect data quickly
  • Learn and teach programming concepts

Frequently asked questions

Is WebSocket & SSE Realtime Tester free?

Yes, 100% free with no limits. Online Free Tools is a free welfare project supported only by ads. Full power is unlocked by inviting friends, never by paying.

Are my files uploaded?

No. WebSocket & SSE Realtime Tester runs inside your browser, so your data stays on your device.

Does it work on mobile?

Yes. It works in Chrome, Safari, Edge and Firefox on Android, iPhone, Windows and Mac.

Built with open-source technology: websockets/ws.

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No subscriptions. No payments. Ever. Full power is unlocked by inviting friends, never by paying.

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