Today

On a Mac, it's easy enough to use emoji such as ❤️, just by outputting that character to the console. (That's a unicode character, not an image.)

Problem

• Most of the Linux distros don't support them well by default.
• Most of the ssh gateways don't support them at all; e.g: continuous integration/deployment.
• I'm not sure about Windows, but I'm guessing support isn't there or isn't great.

Solution

supports-emoji library, similar to supports-color.

const supportsEmoji = require('supports-emoji');
console.log(`I ${supportsEmoji ? '❤️' : '<3'} your work!`);

Note: it looks like Github code blocks don't support emoji. That block is a ❤️ too.