Run Scripts on websites using this simple technique

What are bookmarklets?

A bookmarklet is a bookmark stored in a web browser that contains JavaScript commands that add new features to the browser.

Developing a bookmarklet is simple and easy to use.

They can even make a post request with the fetch api.

How to develop one

Use javascript in href attribute of <a> tags in HTML.
An example would be

<a href="javascript: alert('hello world');">click me</a>

Make that in HTML and drag it into your bookmarks bar, you have just added a bookmarklet to your browser. Isn't it simple?

All the javascript in your bookmarklet has to be minified.

<a href="javascript: fetch('https://api.website.com/endpoint').then((data) => { alert('data'); })"></a>

Bookmarklet can be used to modify(or filter) the content of a website.
Below is an example:

<a href="javascript: document.body.innerHTML = '<h1>yeah!</h1>' })"></a>

Main reason you should consider developing or using a bookmarklet is for productivity.

You can find many pre-built bookmarklets on internet.

I hope this helps someone out there.

Don't forget to mention what you've made in the comments below!