Bootstrap vs Bulma (2026): Which CSS Framework to Use?

Bootstrap and Bulma are both component frameworks: you add a stylesheet and get a responsive grid, buttons, forms, navbars, cards, and modals with readable class names. The big differences are that Bootstrap ships its own JavaScript for interactive components while Bulma is CSS only, Bootstrap has a much larger ecosystem, and Bulma’s class names read more like plain English (button is-primary is-large). This guide compares Bootstrap 5.3.9 and Bulma 1.0.4, the latest versions in November 2026, on syntax, grid, components, JavaScript, customization, size, and ecosystem.

The short answer

Choose Bootstrap if:

• You need interactive components, such as modals, dropdowns, tooltips, carousels, and collapsible navbars, that work without writing JavaScript.
• You want the largest ecosystem: themes, templates, tutorials, React and Vue libraries, and answers to almost any question.
• You want a smaller default stylesheet: about 31 KB gzipped, against about 65 KB for Bulma.
• You want a framework that’s actively developed, with Bootstrap 6 in alpha.

Choose Bulma if:

• You want pure CSS and plan to write your own JavaScript, or use a framework like Vue or React that handles interaction.
• You like modifier classes such as is-primary, is-large, and has-text-centered.
• You want a modern CSS-grid layout helper (grid and cell) alongside flexbox columns.

Bootstrap vs Bulma at a glance

	Bootstrap 5.3.9	Bulma 1.0.4
Latest release	November 2026	April 2025
License	MIT	MIT
GitHub stars	About 175,000	About 50,000
JavaScript	Included (modals, dropdowns, tooltips, carousel, collapse, and more)	None, CSS only
Minified CSS, gzipped	About 31 KB	About 65 KB (about 50 KB without helpers)
Grid	12-column flexbox grid with row and col-*	Flexbox columns, plus CSS grid with grid and cell
Breakpoints	576, 768, 992, 1200, 1400px	769, 1024, 1216, 1408px
Dark mode	data-bs-theme="dark"	Automatic with prefers-color-scheme, or data-theme="dark"
Customization	Sass variables, CSS variables, utilities API	Sass modules, CSS variables
Class style	btn btn-primary btn-lg	button is-primary is-large

GitHub star counts are rounded, from November 2026. The CSS sizes are what we measured from each package’s minified stylesheet.

Syntax side by side

The same button in each:

<!-- Bootstrap -->
<button class="btn btn-primary btn-lg">Sign up</button>

<!-- Bulma -->
<button class="button is-primary is-large">Sign up</button>

Bootstrap names variants with the component as a prefix (btn-primary, alert-danger). Bulma uses a base class plus is-* and has-* modifiers that read like a sentence. A notification:

<!-- Bootstrap -->
<div class="alert alert-success">Saved.</div>

<!-- Bulma -->
<div class="notification is-success">Saved.</div>

Spacing helpers are almost identical in both: mt-3, px-4, and mb-0 work in each, though the spacing scales differ.

Grid and layout

Both use 12 columns on flexbox. A two-column layout that stacks on phones:

<!-- Bootstrap -->
<div class="row">
  <div class="col-md-6">Left</div>
  <div class="col-md-6">Right</div>
</div>

<!-- Bulma -->
<div class="columns">
  <div class="column is-half">Left</div>
  <div class="column is-half">Right</div>
</div>

Bulma’s columns stack below 769px by default, and equal columns need no size at all: every column in a columns row shares the space. Bootstrap’s col does the same. Responsive sizes use a breakpoint suffix in Bulma (is-6-tablet, is-4-desktop) and an infix in Bootstrap (col-md-6, col-lg-4).

Bulma 1.0 also has a CSS grid helper: grid with cell children makes a responsive grid of equal tiles without setting column counts. Bootstrap’s d-grid and gap-* utilities cover simpler CSS grid layouts. The Bootstrap grid guide covers Bootstrap’s side.

Breakpoints differ: Bulma’s tablet starts at 769px and desktop at 1024px, while Bootstrap’s md is 768px and lg is 992px.

Components

Both include buttons, forms, cards, navbars, tabs, breadcrumbs, pagination, dropdowns, modals, messages or alerts, progress bars, tables, and tags or badges. Bulma adds a few layout pieces, such as hero for large banners, level for horizontal bars, media for comment-style objects, and skeleton loaders. Bootstrap adds components Bulma doesn’t have: carousel, accordion, offcanvas, toasts, tooltips, popovers, spinners, and placeholders.

JavaScript: the biggest difference

Bootstrap’s components work out of the box. Add the bundle, and a modal opens from a button with only data attributes:

<button class="btn btn-primary" data-bs-toggle="modal" data-bs-target="#signup">Open</button>

Bulma ships no JavaScript. Its modal, dropdown, and mobile navbar menu are styled, but you write the code that opens and closes them, usually by toggling the is-active class:

document.querySelector('.navbar-burger').addEventListener('click', e => {
  e.currentTarget.classList.toggle('is-active');
  document.getElementById(e.currentTarget.dataset.target).classList.toggle('is-active');
});

That’s simple for a navbar, but focus trapping in modals, keyboard support in dropdowns, and positioning tooltips take real work. Bootstrap’s components handle these, including the accessibility details. In a React or Vue app, where you’d write that logic anyway, Bulma’s CSS-only approach matters less.

Customization and theming

Both are built with Sass and expose CSS variables.

• Bootstrap uses Sass variables such as $primary, the $theme-colors map, and the utilities API, plus --bs-* CSS variables at runtime. You can also change a theme visually in the bootstrap.build builder and export the Sass or CSS. See how to customize Bootstrap 5.
• Bulma 1.0 moved to Sass modules (@use) and generates thousands of --bulma-* CSS variables, so colors and many component values can change at runtime. Its colors are defined with hue, saturation, and lightness variables.

For dark mode, Bulma follows the system setting automatically with prefers-color-scheme, or a data-theme="dark" attribute. Bootstrap 5.3 uses data-bs-theme="dark" and needs a few lines of JavaScript to follow the system setting; the dark mode guide shows how.

Size and performance

Stylesheet	Minified	Gzipped
Bootstrap 5.3.9 bootstrap.min.css	232 KB	31 KB
Bulma 1.0.4 bulma.min.css	678 KB	65 KB
Bulma 1.0.4 bulma-no-helpers.min.css		50 KB
Bootstrap 5.3.9 bootstrap.bundle.min.js		About 24 KB

Bulma’s full stylesheet is about twice Bootstrap’s, mostly because of its helper classes and CSS variables. With Sass, both can be trimmed to only the parts you use. Bootstrap’s JavaScript is extra, but you’d write or add some JavaScript with Bulma too. The Bootstrap CSS size guide shows how to shrink Bootstrap.

Ecosystem and maintenance

Bootstrap is the most widely used CSS framework, with thousands of themes and templates, official and community React and Vue libraries such as React Bootstrap and BootstrapVue, and regular releases: 5.3.9 shipped in November 2026, and Bootstrap 6 is in alpha.

Bulma has a smaller but loyal community and some Vue and React wrappers. Its latest release, 1.0.4, was in April 2025, and the repository is still updated.

Should you switch?

From Bulma to Bootstrap, if you’re tired of writing JavaScript for modals, dropdowns, and menus, or want more templates and help. From Bootstrap to Bulma, if you want a CSS-only framework for an app where React or Vue handles every interaction, and you prefer its class names.

If you’re also weighing a utility-first framework, see Bootstrap vs Tailwind and our overview of CSS frameworks.

FAQ

Is Bulma better than Bootstrap?

Neither is better for everything. Bootstrap is better if you want interactive components without writing JavaScript, a smaller default stylesheet, and the largest ecosystem. Bulma is better if you want a CSS-only framework with readable modifier classes and plan to handle interaction yourself.

Does Bulma use JavaScript?

No. Bulma is CSS only. Components such as the modal, dropdown, and mobile navbar menu are styled, but you add your own JavaScript to open and close them, usually by toggling the is-active class.

Is Bulma still maintained?

Yes. Bulma 1.0, released in 2024, rebuilt it with Sass modules and CSS variables, and the latest version is 1.0.4 from April 2025. The GitHub repository is still active, but releases are less frequent than Bootstrap’s.

Is Bulma lighter than Bootstrap?

No. Bulma 1.0.4’s full minified stylesheet is about 65 KB gzipped, against about 31 KB for Bootstrap 5.3.9. Bulma’s build without helpers is about 50 KB. Bootstrap adds about 24 KB of JavaScript if you use its interactive components.

Can I use Bootstrap and Bulma together?

It isn’t recommended. Both define classes such as button, columns, navbar, card, and spacing helpers, and both reset base styles, so they conflict. Pick one, or use Bulma’s prefixed build if you must load both during a migration.

What is the Bulma equivalent of Bootstrap’s col-md-6?

column is-6-tablet or column is-half-tablet inside a columns container. Note that Bulma’s tablet breakpoint starts at 769px, one pixel above Bootstrap’s 768px md breakpoint.