To stop FitVids from resizing one video, wrap the video in an element with the class fitvidsignore. In post and page content, FitVids makes YouTube, Vimeo and Kickstarter videos, and object and embed elements, fill the width of their container. This can make a video wider than the size in its embed code.
FitVids is a feature of Polestar, Ultra and the Puro theme. It is not part of WordPress core, so a block theme has it only if the theme adds it.
Classic Admin Screens
In the Classic Editor, open the Text tab and wrap the embed code. A Custom HTML block works the same way.
<div class="fitvidsignore"> <iframe src="https://www.youtube.com/embed/VIDEO_ID" width="560" height="315" frameborder="0" allowfullscreen></iframe> </div>
The video now shows at the size in its embed code. Other videos on the page keep the FitVids behavior.
Customizer
To turn FitVids off for the whole site, use the theme setting. Polestar has no setting and always loads FitVids.
- The Puro theme: AppearanceCustomizeTheme SettingsLayout, then clear Enable FitVids.js. It is on by default.
- Ultra: AppearanceCustomizeTheme SettingsLayout, then clear FitVids.js. It is on by default.
Block Themes and the Block Editor
In the block editor, put the video in a Group block. Open Advanced in the block settings and enter fitvidsignore in Additional CSS class(es). The class works wherever the theme loads FitVids.
Tableau Embeds
The themes skip elements with the class tableauViz. FitVids targets only the video types listed above, so Tableau iframes keep their size.