email-minifier

EmailMinifier

EmailMinifier is a well-tested email minifier based on TypeScript for browser and Node.js

https://github.com/luckrnx09/email-minifier/assets/113882203/2f2ad00e-73d8-437e-b357-7505b9d9e78a

As a quick start, you can Try it online 🚀

Why not HTMLMinifier

HTMLMinifier is a great tool for compressing HTML. But email is different from HTML in many ways, compression of HTML is often not the best solution.

• JavaScript code is not supported or required in emails.
• The interactive behavior of the email is very limited, most HTML attributes are useless for the email but still load them when user open it.
• Some email clients crop oversized emails (e.g. Gmail) and the style of the email is broken after cropping, which is extremely detrimental to marketing.
• ...

Installation

You can use the tool you like to install EmailMinifier:

npm

npm install email-minifier 

yarn

yarn add email-minifier 

pnpm

pnpm install email-minifier 

Usage

For both browser and Node.js if you use ESM:

import { EmailMinifier } from 'email-minifier';
(async () => { 
    const emailBody = `<div class="hello"></div>`;
    const options = {};
    const result = await new EmailMinifier(emailBody).minify(options);
    console.log(result);
})();

For Node.js only if you use CommonJS:

const { EmailMinifier } = require('email-minifier');
(async () => { 
    const emailBody = `<div class="hello"></div>`;
    const options = {};
    const result = await new EmailMinifier(emailBody).minify(options);
    console.log(result);
})();

The minify() method will returns a Promise with the shape as follow:

{
    original: '', // the original email body string
    minified: '', // minified email body string will be here, if no tasks ran, it'll be null
    tasks: [] // all ran tasks when minify email body
}

All available properties for options are as follows

Option	Description	Default
minifyIds	Minifiy id attributes used in style tags	true
minifyClasses	Minifiy class attributes used in style tags	true
minifyDatasets	Minifiy data-* attributes used in style tags	true
removeUnusedAttrs	Remove custom attributes unused in style tags	false
minifyStyles	Minifiy CSS content for all the style tags	true

For removeUnusedAttrs, if you want to remove the specific unused attributes, you can provide an array with RegExp instances to match them.

For example:

const options = {
    removeUnusedAttrs: [
        new RegExp('custom-test-id') // Remove `custom-test-id` attributes if they not used in style tags
    ]
};

Performance

The following table shows the statistics in the Node.js environment

Email	Original Size	Minified Size	Elapsed Time
Holiday Cheer	33.09kb	32.36kb	580.30ms
Membership Discount	104.00kb	37.97kb	93.61ms
Movies for Christmas	289.47kb	58.30kb	138.13ms

The emails above are generated from unlayer.

License

See LICENSE