What are Web Workers?

• Web Workers helps us to run javascript code in the background without blocking application.
• Web Workers runs in an isolated (new) thread for executing our javascript code.
• Web Workers are usually used for large tasks.
• Web Workers needs a seperate file for our javascript code.
• Web Workers files are downloaded asynchronously.
• Web Workers are supported in all latest browser.

Example:

Our client side js file below:

var myWebWorker = new Worker("task.js"); // Creating a worker

// Listen to task.js worker messages
worker.addEventListener("message", function(event) {
  console.log("Worker said: ", event.data);
}, false);

worker.postMessage("From web worker file"); // Will start the worker

task.js (worker file) file below:

// Listen to client js file post messages
self.addEventListener("message", function(event) {
  self.postMessage(event.data); // Send processed data to listening client js file.
}, false);