The Bootstrap 4 + WordPress Theme Framework

UnderStrap combines the Underscores starter theme (by Automattic) and the mobile-first, responsive grid framework
Bootstrap 4 (by Twitter) into a perfect open source foundation for your next WordPress theme project.

Download NEW!: 0.9.4
...or view source on GitHub
Holger - The Developer of UnderStrap
Holger, Developer of UnderStrap

"I´am a Frontend Dev and UX Designer working with WordPress and responsive frameworks daily. Instead of starting again and again from scratch I decide to combine my two most used tools into one:"

Underscores starter theme

Based on the "best-practices" starter theme Underscores, or just "_s" - Made by Automattic, the company behind WordPress.

Bootstrap 4 Grid framework

Uses Bootstrap 3 Bootstrap 4 for markup and CSS styles - THE industry standard for responsive and mobile friendly websites.


Utilizes the SASS sources from all assets as well as own SASS files. Makes it easy to replace colors, fonts, stylings etc.

npm New

Comes with npm support to manage all the dependencies. Just one command in your terminal is needed to update all assets.

Gulp New

Comes with Gulp as task runner and one pre-made gulpfile.js with some default tasks. For example to compile SASS to CSS.

Selected Features:

Options Panel

Let you add custom code right from your WordPress customization panel. You can also control the slider settings. More options coming soon.

Font Awesome

Comes with Font Awesome 4.6+ font icon kit as dependency. A huge and free (MIT License) set with over 600 icons.

Jetpack ready

Comes with basic theme support for the famous plugin bundle by Automattic. No extra styles or settings but you can use both in combination.

WooCommerce support New

UnderStrap supports WooCommerce plugin. WooCommerce is the #1 e-commerce system for WordPress (more than 1.000.000 active installs).

Child Theme ready New

UnderStrap is made as solid Parent theme with Child Themes in mind. A basic Child Theme is already available here.

Translation ready New

Uses the WordPress best-practices to keep theme text´s translatable. Comes with english and german language file by default.

Open Source

Released under GNU General Public License v2 ( Details here ) UnderStrap is free to use for personal and commercial projects which are compatible with this license.

Build-in slider

Comes with build-in widget slider and basic settings for it. Based on Owl Carousel 2 by Bartosz Wojciechowski.

Blank Child Theme (v0.5.4) New

A separate Child Theme is available on GitHub. It is build on top of UnderStrap and use it´s PHP files but comes with it´s own styling possibilities and dependencies. A blank canvas for your styling.

Download Child Theme

Ready To Download The Latest UnderStrap?

Download v.0.9.4