Most eligible Liquid storefronts got a modest speed boost automatically. Shopify now sends the first part of the page sooner, but the theme determines how much of that head start turns into faster rendering for shoppers.

  • What changed: On September 22, 2026, Shopify's performance team published a post by Mateusz Krzeszowiak (@krzksz) explaining the change. Shopify now sends everything in a theme's layout up to {{ content_for_header }} to the browser right away, and the rest of the page follows once the template finishes rendering. For the median store, TTFB (the time until the server's first response) fell 29% at p75 and 21% at p90. FCP and LCP (when the first content and the main content appear) improved 2–6% (Performance @ Shopify).
  • What it does not change: "None of this changes how much work the server does," the post notes; streaming changes when the browser receives the output. That is why a 29% faster first byte turns into a single-digit gain in what shoppers see.
  • Why does the asterisk matter? The announcement says "No theme changes needed*". The head start only speeds up visible loading if the theme's stylesheets and fonts sit above {{ content_for_header }}. At p75, Horizon gained 29% on TTFB, 8% on FCP and 4% on LCP. Dawn, which loads base.css below that tag, gained 25%, 3% and 2%. @sh_sakamoto highlighted the roughly threefold FCP gap for merchants. Pages built from .liquid template files and stores with a filtered, conditional or nested content_for_header are not streamed.
  • What to do this week: Ask your developer to follow Shopify's performance guide, Load first-paint resources before content_for_header, and test the change on a theme copy before publishing. Moving resources above the tag is not risk-free: Shopify warns that inline scripts reading Shopify.* will throw there, and moved stylesheets can lose specificity ties against the styles Shopify injects. Record mobile FCP and LCP before and after.

Do I need to do anything to get the speed boost?

Not for the faster first response, which Shopify applies automatically to most eligible pages. To turn it into visibly faster loading, your theme has to load critical CSS and fonts before {{ content_for_header }}, and that change should be tested on a theme copy because it can break scripts or styling that depend on the current order.

Why does Horizon benefit more than Dawn?

Horizon defines its stylesheets and fonts before {{ content_for_header }}, so the browser starts downloading them during the head start. Dawn places base.css below the tag, so its CSS arrives with the rest of the page, which is why its FCP gain was 3% against Horizon's 8%.

Will this raise my conversion rate?

There are no public figures linking this change to conversion rate yet. The visible gains are small, so treat it as a free improvement rather than a fix for pages slowed down by heavy images or third-party scripts.