Test Server-Sent Events endpoints in real-time, view event streams, parse data, and monitor connection status
Zero Dependencies·Works Offline🔗 Connection Settings
📋 Event Log
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What can SSE Tester do?
SSE Tester is a free online tool that helps developers test Server-Sent Events endpoints in real-time. Enter an SSE endpoint URL and the tool establishes an EventSource connection, displaying received event stream data including event types, data content, and connection status - essential for debugging SSE server push functionality.
Core Features
- Real-time Connection: Establish SSE connections using EventSource API
- Event Monitoring: Display all received event types and data in real-time
- Connection Status: Monitor connection state, event count, and duration
- Auto Reconnect: Support SSE protocol's auto-reconnect mechanism
- Event ID Tracking: Display last received event ID
- JSON Parsing: Auto-parse JSON-formatted event data
Use Cases
Case 1: AI Streaming Output Debugging
Test streaming API responses from ChatGPT/Claude AI models, view token output and completion events in real-time.
Case 2: Real-time Notification Service
Debug server push notification systems, verify event formats and push frequency.
Case 3: Stock/Data Quotes
Test real-time data push endpoints, verify data formats and push intervals.
FAQ
What is SSE?▼
SSE is an HTML5 server push technology using HTTP connections. It's simpler than WebSocket and ideal for real-time notifications, stock quotes, and AI streaming outputs.
SSE vs WebSocket?▼
SSE is unidirectional (server to client), HTTP-based with auto-reconnect. WebSocket is bidirectional on a separate protocol. SSE is better for server push scenarios.
Why is my SSE connection failing?▼
Common reasons: CORS restrictions, server not returning Content-Type: text/event-stream, incorrect URL. This tool shows detailed errors to help troubleshoot.
Is data uploaded to servers?▼
Connections are direct between your browser and the target server. No data passes through third-party servers.