Tailwind Just-In-Time Compiler

Nick Radford
Nick Radford
Jun 24, 2021
  • 2 min read

Tailwind.css added a compilation mode in v. 2.1 to allow Just-in-Time compilation of the library, removing the need for enabling/disabling different variants or creating new styles for quirky one-offs, in favor of allowing the runtime to determine which styles to package into the build.

The best benefit in my opinion is that all variants are enabled by default, and the unused ones are purged from the final build. This leads to a more natural coding style, as you assume the classes you type will work, instead of needing to stray into configuration to enable the write combination.

Say goodbye to your variants block in tailwind.config.js

- variants: {
- margin: ["responsive", "last"],
- display: ["responsive", "group-hover"],
- opacity: [
-      "responsive",
-      "group-hover",
-      "focus-within",
-      "hover",
-      "focus",
-      "disabled",
-   ],
- },

Instead, just write the classes you need to use in your HTML, and the compiler will figure it out!

// Real example from my contact page
<Button className="disabled:hover:bg-transparent">Send Email</Button>

The next best benefit of using the JIT mode is the arbitrary value support. Have you ever been coding up a UI, just to have an element that sits off the grid, or would just look better if it was scooched to the left 3 pixels?

<img src="some-asset.png" className="relative left-[-3px]" />

With Just-in-Time compilation, you can pass arbitrary values into class names, which will be parsed into its own new class and applied to the element.

It's worth noting that you cannot compute these values, they must be static text in your HTML.

Want to learn more? Read the Tailwind JIT Docs