Is Boostrap CSS file used in Debut theme?

Topic summary

Issue: Google PageSpeed flags an external Bootstrap 3.3.7 CSS (maxcdn) loading on a Shopify store using the Debut theme. The poster can’t find where it’s used in Debut, suspects it may come via a “trekkie” script, and is concerned removal could break functionality.

Findings: Debut does not include Bootstrap by default. The Bootstrap file is likely injected by an installed app or from custom code manually added to the theme, rather than by the theme itself.

Actionable steps: Audit installed apps and their injected script tags for Bootstrap references. Check theme.liquid, layout files, and snippets for any external bootstrap.min.css includes. If removal is desired, disable it at the app level or delete the custom include, noting that it may affect that app’s UI.

Status: Unresolved. Guidance indicates an external app is the probable source; no confirmed removal or fix yet.

Summarized with AI on March 4. AI used: gpt-5.

I’m getting a warning from Google PageSpeed regarding the follow Bootstrap CSS file:

https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css

It is unclear what this is used for in the Debut theme, yet at the same time it is also difficult for me to determine how to remove it - and whether it’ll break something. Anybody has any idea on how to do this? From what I can see, it is part of a trekkie script.

By default Debut theme doesn’t use Bootstrap, if someone did add that manually to the theme files.

It should be another app installed on your Shopify store that inject this code.