Atomic
GitHub
NEWNow supports Joomla 4, 5 & 6

The fastest foundation for any Joomla site.

Atomic is a free, open-source template with 50+ settings, 24 Bootswatch themes, 1500+ Google Fonts, light/dark mode and flexible layouts, and it still scores a perfect 100 on PageSpeed.

View the live demo Get it on GitHub
Free forever (GPL v3) Bootstrap 5 at the core Built-in auto-updates
100PageSpeed score
50+Template settings
20Module positions
24Bootswatch themes
1500+Google Fonts
Who it's for

Simple enough to install and go. Open enough to build anything.

Atomic breaks a template down into its smallest parts so you can put them back together however you like. It keeps custom styling to a minimum, relies on Bootstrap 5 for layout and responsiveness, and treats performance as the top priority.

For site builders

A great site, no code required

Install one package, load the sample data, and start adjusting everything from the Joomla admin.

  • Pick a Bootswatch theme and Google Fonts from dropdowns
  • Upload a logo, set colors, and turn on the light/dark switcher
  • Moving from Cassiopeia? Your modules stay where they are
  • One-click updates through Joomla's update system
For developers

A clean starting point for custom builds

Nothing you don't need, with override hooks everywhere so you can upgrade without losing your changes.

  • Two-layer CSS: core fixes, plus decorative styles you can drop
  • Four code-injection points in <head> and <body>
  • Dedicated user.css / user.js override files
  • Menu alias as body class for per-page targeting
Features

Everything a template should do, and nothing it shouldn't.

Every feature is optional. Turn on what you need and Atomic loads only that.

Design & theming

Change the whole look of your site without writing any CSS.

  • 24 Bootswatch themes, CDN or custom Bootstrap
  • Light, dark and auto modes that follow the OS setting
  • Separate Google Fonts for headings and body
  • Optional glassmorphism, gradients and typography styles

Flexible layouts

One, two or three columns in the header, body and footer.

  • Adjustable grid ratios
  • Fixed-width or fluid container
  • Sticky header on scroll
  • Empty positions collapse automatically

Built for speed

Uses modern loading techniques so pages render quickly.

  • Assets loaded through Joomla's Web Asset Manager
  • Non-render-blocking fonts and icon sets
  • Automatic preconnect hints for CDNs
  • Optionally drop Joomla's default CSS & JS

Mobile first

Looks right on phones and tablets as well as desktops.

  • Off-canvas slide-in mobile menu
  • Supports multiple menu modules
  • Full favicon set for Android, Apple & Microsoft
  • Built-in ScrollReveal animations

SEO & social

Follows best practices for search and social sharing.

  • OpenGraph & Twitter/X cards
  • Schema.org image support
  • GA4 Google Analytics integration
  • Styled, localized 403/404 error pages

Developer friendly

Customize it without forking, and upgrade without losing your changes.

  • Code injection at four hook points
  • Five module chrome styles
  • Component-only view for modals & print
  • Offline page with multi-factor login
Layout

20 module positions. Only the ones you use appear.

Assign a module and the position appears. Leave it empty and the column or row collapses, so there's no wasted space and no extra markup. Try turning the sidebars off:

Switching from Cassiopeia? Turn on the mapped positions and your modules keep working.

alert
header
header-center
header-right
topmenu
hero
breadcrumbs
leftbody
main-top
abovebody
componentyour content
belowbody
main-bottom
rightbody
footer
footer-center
footer-right
Themes

Restyle the whole site with a dropdown.

Choose any of 24 Bootswatch themes and Atomic handles the rest. Each one also works with the built-in light/dark switcher. Here's a preview of a few:

An approximation of each theme. See the real thing in the demo →

Settings

50+ settings in eight tabs.

Everything is in the template style editor, so you don't need to edit any files.

Joomla

Bootstrap source (Joomla, CDN, Bootswatch or custom), Font Awesome version, jQuery toggle.

CSS

Custom CSS files, CSS custom properties and template-level overrides.

Typography

Google Fonts for headings and body, plus size, line height and weight.

Layout

Header columns, content widths, sticky header, fluid or boxed container.

Colors

Header and footer backgrounds, menu alias as body class, body class and ID.

Features

Light/dark switcher, back-to-top button, Google Analytics & Tag Manager.

Meta

Open Graph, Twitter Cards, social sharing image and favicons.

Code

Inject code into the head or body, and override the component.

Performance

Atomic has been the fastest Joomla template since 2009.

On a default Joomla install, Atomic scores 100/100 on Google PageSpeed and gets an A from GTmetrix. Your own extensions and content will affect your score, but Atomic won't hold it back.

  • Assets weighted & ordered via Web Asset Manager
  • Fonts & icons load via media-swap with fallbacks
  • Preconnect to Google Fonts, jsDelivr & more
  • No unnecessary resources, ever
Run PageSpeed on the demo
Get started

Up and running in about a minute.

Atomic installs as a single package containing the template and an optional sample data plugin.

  1. Download the package

    Get the latest pkg_atomic_VERSION.zip from GitHub Releases.

  2. Install in Joomla

    Go to System → Install → Extensions and upload the ZIP.

  3. Add sample content (optional)

    Under System → Sample Data, activate Atomic to get a site like the demo.

  4. Make it yours

    Open the template style and choose your theme, fonts, layout and features.

Or build it from source
# Clone the repo
git clone https://github.com/Kontent/Atomic.git
cd Atomic

# Build installable packages into ZIP/
bash build_package.sh
Joomla4.x, 5.x & 6.x
PHP7.4+ (J4) · 8.1+ (J5/6)
History

Actively maintained for over 15 years.

2009

Ron Severdia creates Atomic for Joomla 1.5 as a minimal framework to build templates from.

2012

Atomic ships as a core template in Joomla 2.5.

J3 & J4

Rebuilt around Bootstrap, with a focus on performance and a 100/100 PageSpeed score.

Today

Rewritten for Joomla 4, 5 and 6 on Bootstrap 5, with 50+ settings and auto-updates.

FAQ

Questions, answered.

Is Atomic really free?

Yes. It always has been, and always will be. Atomic is released under the GNU General Public License v3.0.

Which versions of Joomla does it support?

Joomla 4.x, 5.x and 6.x. Joomla 4 requires PHP 7.4 or later; Joomla 5 and 6 require PHP 8.1 or later.

Is it really the fastest Joomla template?

On a default Joomla installation, Atomic scores 100/100 on Google PageSpeed and gets an A from GTmetrix. Your own extensions and content will affect performance, but Atomic keeps its own footprint as small as possible. Test the demo yourself.

I'm using Cassiopeia. Do I have to reassign all my modules?

No. Enable the Cassiopeia-compatible positions in the template settings and your existing module assignments keep working.

Can I add my own code without losing it on upgrade?

Yes. You can inject code after the opening <head>, before </head>, after <body> and before </body>. Dedicated custom CSS and JS files are also kept separate from the template core, so updates won't overwrite them.

Which libraries can I use?

Joomla's built-in Bootstrap 5, a CDN copy, a custom URL, or any of the 24 Bootswatch themes. Font Awesome (including version 7 via CDN) and Bootstrap Icons are optional, and so is jQuery.

How do updates work?

Atomic uses Joomla's built-in update system, so new versions appear alongside your other extension updates. There's also an optional beta channel if you want new features early.

See Atomic in action.

Try the live demo, or download it from GitHub and have it running on your site in minutes.

View the live demo Download from GitHub