Theme Drift: Compare & Diff
A Shopify app for comparing theme files, two or three at once.
Theme Drift: Compare & Diff lets you compare two Shopify themes side by side, or three at once: the original theme, your customized live theme, and a new theme version. When a theme you've customized gets an update, it's hard to tell which changes are your own edits and which are new from the developer. The app shows all versions together, and flags any file where you and the update both changed the same thing, so you can bring your customizations forward safely.
Standard two-theme comparison, and the full file list with conflict status in three-way mode, are always free. The line-by-line diff view in three-way mode is a one-time unlock — no subscription.