Replit ui

WebSocket Connection Failed on Replit

WebSocket connections fail with network errors or close immediately. Real-time features like chat or notifications don't work.

WebSocket configuration and deployment differences between local and Replit cause issues.

Error Messages You Might See

WebSocket connection to 'ws://...' failed Could not upgrade to WebSocket Error: Could not find message broker relay
WebSocket connection to 'ws://...' failedCould not upgrade to WebSocketError: Could not find message broker relay

Common Causes

  1. WebSocket endpoint not exposed or misconfigured
  2. CORS not allowing WebSocket upgrade requests
  3. Proxy/load balancer not forwarding WebSocket protocol
  4. Client using wrong WebSocket URL (ws instead of wss, or localhost)
  5. StompBroker not configured for Spring WebSocket

How to Fix It

For Spring WebSocket, use WebSocketConfigurer and registerStompEndpoints(). Enable CORS with allowed origins. Client should use 'wss://' (secure WebSocket) on Replit. Verify endpoint path matches client connection URL. Check browser console for actual error message and upgrade handshake details.

Real developers can help you.

Matt Butler Matt Butler Software Engineer @ AWS Nam Tran Nam Tran 10 years as fullstack developer Stanislav Prigodich Stanislav Prigodich 15+ years building iOS and web apps at startups and enterprise companies. I want to use that experience to help builders ship real products - when something breaks, I'm here to fix it. hanson1014 hanson1014 Full-stack developer experienced in fixing and deploying AI-generated apps from Lovable, Bolt.new, Cursor, and Replit. I specialize in debugging Supabase integration issues (auth flows, RLS policies, database connections), fixing broken deployments, resolving routing/blank screen problems, and cleaning up messy React/Vite codebases. I also build production apps with the Claude API and have shipped a Mac desktop dev tool (Nexterm from scratch. Based in Hong Kong, fast turnaround. Jared Hasson Jared Hasson Full time lead founding dev at a cyber security saas startup, with 10 yoe and a bachelor's in CS. Building & debugging software products is what I've spent my time on for forever BurnHavoc BurnHavoc Been around fixing other peoples code for 20 years. ISHANTDEEP SINGH ISHANTDEEP SINGH Senior Software Engineer with 7+ years of experience in React, JavaScript, TypeScript, Next.js, and Node.js. I’ve also worked as a tech lead for startups, owning end-to-end technical execution including architecture, development, scaling, and delivery. I bring a strong mix of hands-on coding, product thinking, and technical leadership, and I’m comfortable building products from scratch as well as improving and scaling existing systems. rayush33 rayush33 JavaScript (React.js, React Native, Node.js) Developer with demonstrated industry experience of 4+ years, actively looking for opportunities to hone my skills as well as help small-scale business owners with solutions to technical problems prajwalfullstack prajwalfullstack Hi Im a full stack developer, a vibe coded MVP to Market ready product, I'm here to help Bastien Labelle Bastien Labelle Full stack dev w/ 20+ years of experience

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Frequently Asked Questions

Should I use ws:// or wss:// on Replit?

Use wss:// (secure) on production. Client auto-detects based on page protocol

How do I configure Spring WebSocket?

Implement WebSocketConfigurer, register endpoint with registerStompEndpoints()

Related Replit Issues

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