Enable monitoring
Turn on the 404Guard app embed in the theme editor without editing theme code.
Monitoring is an app embed. It runs in the theme head, adds no visible storefront content, and only reports a visit when Shopify says the current page type is 404.
From the app
- Open 404Guard in Shopify Admin.
- If monitoring is inactive, choose Enable 404Guard. Settings uses the same theme editor link, labeled Open Theme Editor.
- In the theme editor, confirm the 404Guard embed is enabled.
- Save the theme.
- Back in 404Guard, choose Check monitoring. The badge should read Monitoring active.
Themes
Online Store 2.0 themes support app embeds. Many vintage themes do too. If the theme editor has no app embed section, the theme cannot run 404Guard until it is updated or replaced. Detection does not depend on English text in the theme.
If the status stays inactive
Save the theme after enabling the embed, including unpublished themes you are previewing only if that is the theme shoppers use. Password-protected development stores still report 404s to someone who can open the storefront. Check monitoring reads the embed state from Shopify. It does not invent an active state.