Written by SnapIT SaaS | October 23, 2025 | 7 min read
WebSockets enable instant, bidirectional communication between browsers and servers. Learn how to build real-time chat, live notifications, and collaborative editing with WebSocket APIs and AWS infrastructure.
Traditional HTTP polling wastes bandwidth and adds latency:
Scenario: 1,000 concurrent users, 1 update per minute
HTTP Polling (1s interval):
Requests: 60,000/minute (1,000 users x 60 polls)
Data transferred: ~12 MB/min (overhead)
Server load: High (constant request processing)
Latency: 0-1000ms (depends on poll timing)
WebSockets:
Requests: 1,000 connections (persistent)
Data transferred: ~50 KB/min (only actual updates)
Server load: Low (idle connections)
Latency: under 50ms (instant push)
Result: ~98% reduction in server requests# Create WebSocket API
aws apigatewayv2 create-api \
--name "SnapIT-Chat-WebSocket" \
--protocol-type WEBSOCKET \
--route-selection-expression '$request.body.action'
# Routes:
# $connect -> onConnect Lambda (authenticate user)
# $disconnect -> onDisconnect Lambda (cleanup)
# sendMessage -> sendMessage Lambda (broadcast to users)
# $default -> default Lambda (error handling)// DynamoDB Table: WebSocketConnections
{
connectionId: "abc123def456", // Primary Key
userId: "user_789",
roomId: "room_general",
connectedAt: 1697654400000,
ttl: 1697740800 // Auto-delete after 24 hours
}
// onConnect Lambda
exports.handler = async (event) => {
const connectionId = event.requestContext.connectionId
const userId = event.queryStringParameters.userId
await dynamodb.put({
TableName: 'WebSocketConnections',
Item: { connectionId, userId, connectedAt: Date.now(),
ttl: Math.floor(Date.now() / 1000) + 86400 }
}).promise()
return { statusCode: 200, body: 'Connected' }
}import { useEffect, useState } from 'react'
const ChatApp = ({ userId, roomId }) => {
const [ws, setWs] = useState(null)
const [messages, setMessages] = useState([])
const [input, setInput] = useState('')
useEffect(() => {
const wsUrl = 'wss://your-api-id.execute-api.us-east-1.amazonaws.com/prod'
+ '?userId=' + userId + '&roomId=' + roomId
const socket = new WebSocket(wsUrl)
socket.onmessage = (event) => {
const message = JSON.parse(event.data)
setMessages(prev => [...prev, message])
}
setWs(socket)
return () => socket.close()
}, [userId, roomId])
const sendMessage = () => {
ws.send(JSON.stringify({
action: 'sendMessage', roomId, userId,
message: input, timestamp: Date.now()
}))
setInput('')
}
// ... render messages and input
}const apiGateway = new AWS.ApiGatewayManagementApi({
endpoint: process.env.WEBSOCKET_ENDPOINT
})
exports.handler = async (event) => {
const { roomId, userId, message } = JSON.parse(event.body)
// Get all connections in room
const connections = await dynamodb.query({
TableName: 'WebSocketConnections',
IndexName: 'roomId-index',
KeyConditionExpression: 'roomId = :roomId',
ExpressionAttributeValues: { ':roomId': roomId }
}).promise()
// Broadcast message to all room members
await Promise.all(
connections.Items.map(conn =>
apiGateway.postToConnection({
ConnectionId: conn.connectionId,
Data: JSON.stringify({ userId, message, timestamp: Date.now() })
}).promise().catch(err => {
if (err.statusCode === 410) {
// Stale connection, remove from DB
dynamodb.delete({ TableName: 'WebSocketConnections',
Key: { connectionId: conn.connectionId } }).promise()
}
})
)
)
return { statusCode: 200, body: 'Message sent' }
}Push alerts to users instantly:
Real-time document collaboration like Google Docs using Operational Transformation (OT) for conflict resolution and cursor position broadcasting.
Real-time metrics for analytics platforms:
// Validate JWT token in $connect route
const jwt = require('jsonwebtoken')
exports.handler = async (event) => {
const token = event.queryStringParameters.token
try {
const decoded = jwt.verify(token, process.env.JWT_SECRET)
await storeConnection(event.requestContext.connectionId, decoded.userId)
return { statusCode: 200 }
} catch (error) {
return { statusCode: 401, body: 'Unauthorized' }
}
}Scenario: Chat app with 10,000 concurrent users, 1 million messages per day
SnapIT products like ChatFly and ForumFly use WebSocket architectures like the one described above. See the full SnapIT product suite for real-time tools built on AWS serverless infrastructure.
Explore SnapIT SaaS Products →WebSockets transform user experience with instant updates and real-time collaboration. AWS API Gateway + Lambda + DynamoDB provides a scalable, cost-effective infrastructure for chat apps, live notifications, and collaborative tools. With low latency and far fewer server requests than HTTP polling, WebSockets are worth the added complexity for any app that needs real-time features.