How to make a chrome extension

Hello All, I am new in this community and I want to make a chrome extension. Can someone how does long it takes to publish and how I can build manifest.json file?

The hardest part is merely wrapping your head around what exactly constitutes a Chrome extension. And, simply, that’s these files (usually) for a standard extension:

A manifest file (named manifest.json), which contains meta-data about your extension. That is, its name, version, description, what icons it uses, etc.
A background script. This is merely an HTML file that continuously runs in the background. Usually you want to have some Javascript checking for some event you want to interact with.
A popup page, which, in the simplest case, is going to be a "browser action" (enabled all the time). This is another simple HTML file, which is displayed when you click the extension's icon.

At the very least, you’ll need a manifest file and either a background script or a popup page – it’s not required to have all three.

Here’s a simple manifest file:

"name": "Awesome extension",
"version": "",
"description": "Example extension for Mr. Anon",
"background_page": "background.html",
"browser_action": { "popup": "popup.html" },
"permissions": [ ]

If you’ve got knowledge of HTML already, throw together a quick, little page and name it popup.html. Put everything in the same folder and follow these steps to add your extension to Chrome:

Click the wrench in the top right and navigate Tools > Extensions.
Click Developer mode in the top right.
Click the Load unpacked extension... button and navigate to the folder you saved your files in.
Click OK.

Thanks @Rohan_Joshi this is very useful to me. I have checked this post also to make a chrome extension.