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ProtocolCodes
1000
WebSocket

1000 Normal Closure

The connection has been closed cleanly, meaning the purpose for which it was established has been fulfilled. Both endpoints agree the session is complete.

On this page

When You See This Code

The WebSocket connection closed gracefully after both sides finished exchanging data. This is the expected close code for a successful session.

How to Fix

No fix needed — this indicates everything worked as intended. If you did not expect the connection to close, check your application logic for premature close() calls.

Specification

View RFC / Specification →

Compare With

1001 Going Away 1002 Protocol Error 1003 Unsupported Data 1005 No Status Received 1006 Abnormal Closure 1007 Invalid Payload Data 1008 Policy Violation 1009 Message Too Big 1010 Mandatory Extension 1011 Internal Error 1012 Service Restart 1013 Try Again Later

Guides

Debugging CORS Errors: A Developer's Guide Debugging & Troubleshooting
Debugging WebSocket Disconnections Debugging & Troubleshooting
WebSocket Close Codes: Why Your Connection Dropped Real-Time Protocols
WebSocket Authentication Patterns Real-Time Protocols
WebSocket vs Server-Sent Events: Choosing the Right Protocol Real-Time Protocols
WebRTC Signaling with SIP and WebSocket Real-Time Protocols
gRPC Streaming vs REST Polling: Real-Time Data Delivery Real-Time Protocols
MQTT Protocol: Lightweight Messaging for IoT and Real-Time Systems Real-Time Protocols
WebSocket Performance Tuning Performance & Optimization
RFC 6455: WebSocket Protocol Deep Dive Protocol Deep Dives
RFC 9114: HTTP/3 Protocol Deep Dive Protocol Deep Dives
QUIC Protocol: The Transport Layer Behind HTTP/3 Protocol Deep Dives
TLS 1.3: Faster, Simpler, More Secure Protocol Deep Dives
Migrating from WebSocket to Server-Sent Events Migration & Upgrades
Reverse Proxy Configuration: Nginx, Caddy, and HAProxy Production Infrastructure
Connection Draining: Graceful Shutdown Without Dropping Requests Production Infrastructure
API Gateway Patterns: Architecture and Use Cases API Gateway Patterns
API Gateway Request Routing: Path, Header, and Content-Based API Gateway Patterns
Request and Response Transformation at the API Gateway API Gateway Patterns
CORS Handling at the API Gateway API Gateway Patterns
API Security Testing: OWASP ZAP, Burp Suite, and Automated Scanning Testing & Mocking

Debugging Scenarios

WebSocket 1006 Abnormal Closure Intermediate

Specifications

RFC 6455 The WebSocket Protocol

Decision Guides

Which WebSocket Close Code Should I Use? Which Protocol Should I Use?

Glossary

GraphQL CORS (Cross-Origin Resource Sharing) Port Number Latency NAT (Network Address Translation) Socket Bandwidth Backpressure Thundering Herd Request-Response Model RFC (Request for Comments) Protocol Upgrade Multiplexing Message Framing Full-Duplex WebSocket Frame WebRTC (Web Real-Time Communication) Signaling ICE Candidate WebSocket Subprotocol WebSocket Ping/Pong WebSocket Close Code STUN (Session Traversal Utilities for NAT) TURN (Traversal Using Relays around NAT) SDP (Session Description Protocol) MQTT (Message Queuing Telemetry Transport) STOMP (Simple Text Oriented Messaging Protocol) RTP (Real-time Transport Protocol) Codec Negotiation

Frequently Asked Questions

What is WebSocket 1000 Normal Closure?

The connection has been closed cleanly, meaning the purpose for which it was established has been fulfilled. Both endpoints agree the session is complete.

When do you see WebSocket 1000 Normal Closure?

The WebSocket connection closed gracefully after both sides finished exchanging data. This is the expected close code for a successful session.

How to fix WebSocket 1000 Normal Closure?

No fix needed — this indicates everything worked as intended. If you did not expect the connection to close, check your application logic for premature close() calls.