# bootstrap.build

> bootstrap.build is a free, open-source, in-browser visual editor for creating Bootstrap 5 themes. Also called a Bootstrap theme generator or Bootstrap customizer: you edit Bootstrap's Sass variables with a live preview, then export clean Sass or compiled CSS. No account and no payment are required.

## What it is

- A visual theme builder for **Bootstrap 5.3**. Edit 1,000+ Sass variables: colors, typography, spacing, components, and the new color-mode (dark mode) options, grouped by component or found instantly with search.
- **Live preview**: every change renders against a full Bootstrap UI kit immediately.
- **Export**: download a clean `_variables.scss`, your custom Sass, or the full compiled `bootstrap.css` / `bootstrap.min.css`.
- **Free themes**: start from ready-made themes (based on Bootswatch) and customize them.
- **Free and open source**: no sign-up, no account, no paywall, no lock-in.

## Key facts

- Price: free ($0).
- Account required: no.
- Bootstrap version: 5.3.8.
- Output formats: Sass (`_variables.scss`, custom Sass) and CSS (`bootstrap.css`, `bootstrap.min.css`).
- License: free for personal and commercial projects. The one condition is keeping a visible "Powered by bootstrap.build" link on sites built with the builder. The underlying Bootstrap and Bootswatch code is MIT-licensed.
- Privacy: no accounts and no personal data collected; only anonymous analytics.

## Pages

- [Home](https://bootstrap.build/): what bootstrap.build is, and the link to open the builder.
- [Open the builder](https://bootstrap.build/app): the editor itself (a browser app).
- [Free Bootstrap themes](https://bootstrap.build/themes/): ready-made Bootstrap 5 themes to open and customize.
- [Customize Bootswatch themes](https://bootstrap.build/bootswatch/): open any of the 18 classic Bootswatch themes in the editor and restyle it.
- [Free Bootstrap templates](https://bootstrap.build/templates/): downloadable Bootstrap templates.
- [Guides](https://bootstrap.build/guides/): practical tutorials on customizing Bootstrap 5.
- [License](https://bootstrap.build/license/): usage terms and the attribution condition.
- [Terms of Use](https://bootstrap.build/terms/)
- [Privacy Policy](https://bootstrap.build/privacy/)

## Guides

- [What is Bootstrap? A Beginner Guide for 2026](https://bootstrap.build/guides/what-is-bootstrap/)
- [Bootstrap vs Tailwind CSS: Which Should You Use?](https://bootstrap.build/guides/bootstrap-vs-tailwind/)
- [AI Prompts for Bootstrap Themes: From Brief to Sass](https://bootstrap.build/guides/ai-bootstrap-theme-prompts/)
- [How to Customize Bootstrap 5: The Complete Guide](https://bootstrap.build/guides/customize-bootstrap-5/)
- [How to Customize Bootstrap 5 Colors](https://bootstrap.build/guides/customize-bootstrap-5-colors/)
- [Bootstrap Sass Variables and the Override Order](https://bootstrap.build/guides/bootstrap-sass-variables/)
- [How to Change Fonts and Typography in Bootstrap 5](https://bootstrap.build/guides/change-bootstrap-5-fonts-typography/)
- [How to Add Dark Mode to a Bootstrap 5 Theme](https://bootstrap.build/guides/bootstrap-5-dark-mode/)
- [How to Build an AI Chat Interface with Bootstrap 5](https://bootstrap.build/guides/bootstrap-ai-chat-interface/)
- [How to Export a Custom Bootstrap Theme and Use It](https://bootstrap.build/guides/export-bootstrap-theme/)
- [How to Shrink Bootstrap's CSS (Import Only What You Need)](https://bootstrap.build/guides/reduce-bootstrap-css-size/)
- [How to Use Flexbox in Bootstrap (d-flex Utilities)](https://bootstrap.build/guides/bootstrap-flexbox-utilities/)
- [Bootstrap Spacing: Margin and Padding Utilities](https://bootstrap.build/guides/bootstrap-spacing-margin-padding/)
- [How to Center a Div in Bootstrap (Every Way)](https://bootstrap.build/guides/center-a-div-bootstrap/)
- [Bootstrap Grid System Explained](https://bootstrap.build/guides/bootstrap-grid-system/)
- [Where to Host Your HTML Website](https://bootstrap.build/guides/where-to-host-html-website/)

## FAQ

**Is bootstrap.build free?** Yes, it is completely free and open source, with no paid plan, trial, or usage limit.

**Do I need an account?** No. There is no sign-up or login; open the builder and start designing immediately.

**Is it a Bootstrap theme generator?** Yes. Theme generator, Bootstrap customizer, theme builder: it edits Bootstrap 5 variables visually and generates a finished theme you can export as Sass or CSS.

**Which version of Bootstrap is supported?** The latest Bootstrap 5.3, including its color-mode (dark mode) variables.

**What can I export?** A clean `_variables.scss`, your custom Sass, or the full compiled `bootstrap.css` / `bootstrap.min.css`.

**Can I use the result commercially?** Yes, for any personal or commercial project. The one condition is keeping a "Powered by bootstrap.build" link on the sites you build with it.