Which pages should be tested?

Test the home, product, and collection templates separately. Their content and code paths differ, so one score cannot represent the entire store.

Should every script be removed?

No. Keep code that earns its place. Load nonessential features later and remove scripts whose business value does not justify their performance cost.

What should be changed first?

Start with the bottleneck supported by the measurements. A slow TTFB points toward Liquid work; a healthy TTFB with slow LCP points toward browser-side content and resources.

How to Audit Shopify Apps for Storefront Speed

Audit Shopify apps by measuring what each app loads on the storefront, whether it blocks rendering, and whether its code remains after uninstall. Keep an app only when its business value is greater than its speed and maintenance cost.

Start with the metrics in the right order

Time to First Byte (TTFB) separates Shopify's Liquid rendering time from later browser work. If TTFB is healthy but Largest Contentful Paint (LCP) is slow, inspect the hero image, fonts, styles, and scripts. Interaction to Next Paint (INP) exposes long JavaScript tasks, while Cumulative Layout Shift (CLS) flags elements that move after the page starts rendering.

Keep essential storefront content in HTML

Product titles, prices, variant controls, navigation, and primary images should arrive in the server-rendered Liquid and HTML. Rebuilding essential content in client-side JavaScript makes it appear later and can weaken both usability and search visibility.

Reduce theme and app overhead

Avoid deeply nested Liquid loops across products, variants, or options. Serve correctly sized images and load below-the-fold media lazily. Review app embeds and third-party scripts, then defer or remove features that do not help the shopper complete a task.

Test one change at a time

Record a baseline for the home, product, and collection templates. Change one bottleneck, publish to a theme copy, and rerun the same test on the same device profile. This keeps a real improvement from being confused with normal score variation.

Source

This checklist follows Shopify's current performance best practices for themes, including its guidance on server-rendered content, Liquid loops, images, and Core Web Vitals.

Frequently asked questions

Which pages should be tested?: Test the home, product, and collection templates separately. Their content and code paths differ, so one score cannot represent the entire store.
Should every script be removed?: No. Keep code that earns its place. Load nonessential features later and remove scripts whose business value does not justify their performance cost.
What should be changed first?: Start with the bottleneck supported by the measurements. A slow TTFB points toward Liquid work; a healthy TTFB with slow LCP points toward browser-side content and resources.