Live Preview

By Lex Li

This article shows how live preview.


The keyboard shortcuts are







Preview to Side

ctrl+k ctrl+r

cmd+k cmd+r


To learn all keyboard shortcuts of this extension, please refer to Keyboard Shortcuts.

Rendering Engines

This extension can compile your source files in the background, and show live preview of the current active document.

The compilation/rendering requires an engine, and currently two of them are supported,

  • DocUtils

  • Sphinx

The choice decides the performance and quality of the preview page.

DocUtils Engine

DocUtils implements the basic reStructuredText syntax, and it can render preview based on just a single page. Therefore, if this engine is used,

  • The rendering speed is super fast.

  • The preview page lacks of themes.

  • Certain Sphinx syntax is not rendered correctly.


Sphinx implements its own syntax on top of DocUtils, and it compiles the whole project (based on to a website. Therefore, if this engine is used,

  • The rendering speed can be slow.

  • The preview page contains themed elements, and matches the final result in web browsers.

  • All Sphinx syntax and even extensions work flawlessly.

To learn more about the settings, refer to Configuration.


If a large project is being worked on, the very first preview might take a long time to show, because the first call to Sphinx takes time to generate all HTML pages for all source files.

The subsequent preview pages should be much quicker to show, as those calls to Sphinx only generate the pages that were modified.

More information can be found in this issue .