You're looking at the documentation for Tailwind CSS v2.
Tailwind CSS on GitHub

Max-Width

Utilities for setting the maximum width of an element

Default class reference

Class
Properties
max-w-0max-width: 0rem;
max-w-nonemax-width: none;
max-w-xsmax-width: 20rem;
max-w-smmax-width: 24rem;
max-w-mdmax-width: 28rem;
max-w-lgmax-width: 32rem;
max-w-xlmax-width: 36rem;
max-w-2xlmax-width: 42rem;
max-w-3xlmax-width: 48rem;
max-w-4xlmax-width: 56rem;
max-w-5xlmax-width: 64rem;
max-w-6xlmax-width: 72rem;
max-w-7xlmax-width: 80rem;
max-w-fullmax-width: 100%;
max-w-minmax-width: min-content;
max-w-maxmax-width: max-content;
max-w-prosemax-width: 65ch;
max-w-screen-smmax-width: 640px;
max-w-screen-mdmax-width: 768px;
max-w-screen-lgmax-width: 1024px;
max-w-screen-xlmax-width: 1280px;
max-w-screen-2xlmax-width: 1536px;

Usage

Set the maximum width of an element using the max-w-{size} utilities.

<div class="max-w-md mx-auto ...">
  <!-- ... -->
</div>

Reading width

The max-w-prose utility gives an element a max-width optimized for readability and adapts based on the font size.

Dolore iste eaque molestias. Eius iure ut eaque accusantium. Voluptas repellendus nobis. Saepe nam accusantium magni veniam qui enim mollitia excepturi sapiente.

Dolore iste eaque molestias. Eius iure ut eaque accusantium. Voluptas repellendus nobis. Saepe nam accusantium magni veniam qui enim mollitia excepturi sapiente.

Dolore iste eaque molestias. Eius iure ut eaque accusantium. Voluptas repellendus nobis. Saepe nam accusantium magni veniam qui enim mollitia excepturi sapiente.

<div class="text-sm max-w-prose ...">
  <p>Dolore iste eaque molestias. Eius iure ut eaque accusantium. Voluptas repellendus nobis. Saepe nam accusantium magni veniam qui enim mollitia excepturi sapiente.</p>
</div>

<div class="text-base max-w-prose ...">
  <p>Dolore iste eaque molestias. Eius iure ut eaque accusantium. Voluptas repellendus nobis. Saepe nam accusantium magni veniam qui enim mollitia excepturi sapiente.</p>
</div>

<div class="text-xl max-w-prose ...">
  <p>Dolore iste eaque molestias. Eius iure ut eaque accusantium. Voluptas repellendus nobis. Saepe nam accusantium magni veniam qui enim mollitia excepturi sapiente.</p>
</div>

Constraining to your breakpoints

The max-w-screen-{breakpoint} classes can be used to give an element a max-width matching a specific breakpoint. These values are automatically derived from the theme.screens section of your tailwind.config.js file.

<div class="max-w-screen-2xl">
  <!-- ... -->
</div>

Responsive

To control the max-width of an element at a specific breakpoint, add a {screen}: prefix to any existing max-width utility.

<div class="max-w-sm md:max-w-lg ...">
  <!-- ... -->
</div>

For more information about Tailwind’s responsive design features, check out the Responsive Design documentation.


Customizing

Max-Width Scale

Customize Tailwind’s default max-width scale for the max-w-* classes in the theme.maxWidth section of your tailwind.config.js file.

  // tailwind.config.js
  module.exports = {
    theme: {
      maxWidth: {
+       '1/4': '25%',
+       '1/2': '50%',
+       '3/4': '75%',
      }
    }
  }

The max-w-screen-* classes are derived from the theme.screens section of your tailwind.config.js file.

Learn more about customizing the default theme in the theme customization documentation.

Variants

By default, only responsive variants are generated for max-width utilities.

You can control which variants are generated for the max-width utilities by modifying the maxWidth property in the variants section of your tailwind.config.js file.

For example, this config will also generate hover and focus variants:

  // tailwind.config.js
  module.exports = {
    variants: {
      extend: {
        // ...
+       maxWidth: ['hover', 'focus'],
      }
    }
  }

Disabling

If you don't plan to use the max-width utilities in your project, you can disable them entirely by setting the maxWidth property to false in the corePlugins section of your config file:

  // tailwind.config.js
  module.exports = {
    corePlugins: {
      // ...
+     maxWidth: false,
    }
  }