TTFB Optimization Support – Liquid, Apps, and Store Setup Debugging

Ask Me Anything Q&A Performance101

Topic summary

The discussion centers on optimizing Time to First Byte (TTFB) for a Shopify store experiencing persistently high response times.

Initial Request:
Users seek advanced debugging methods to identify TTFB bottlenecks related to:

  • Liquid theme architecture and server-side rendering
  • Third-party scripts (analytics, tracking)
  • Apps injecting runtime content
  • Internal metrics like render timelines and caching behavior

They acknowledge Shopify’s platform capabilities (sub-500ms TTFB possible) but need deeper diagnostic tools for their specific case.

Official Response:
Shopify staff recommends the Shopify Theme Inspector Chrome extension as the primary diagnostic tool:

  • Provides flame charts showing Liquid code execution during HTML generation
  • Helps identify performance-draining loops or snippets
  • Accessible through Chrome DevTools after authentication

Key Technical Detail:
Shopify does not cache HTML documents or send Cache-Control headers via their CDN (Cloudflare), as pages are treated as dynamic content.

Status: The question receives a partial answer with one recommended tool, though advanced metrics like app injection traceability remain unaddressed.

Summarized with AI on October 28. AI used: claude-sonnet-4-5-20250929.
1

Hi Shopify Team,

We’re currently working on optimizing our store’s Time to First Byte (TTFB) and are looking for more advanced methods to analyze and debug performance bottlenecks. Specifically, we’re interested in understanding how TTFB might be affected by our theme’s Liquid architecture, Shopify’s server-side rendering behavior, and the impact of third-party scripts (e.g., analytics and tracking) and installed apps that inject content at runtime.

We’re aware of Shopify’s strong platform-level performance and the possibility of achieving excellent TTFB scores (even below 500ms), which we greatly appreciate. We’re also familiar with the official Shopify resources on TTFB optimization and Liquid performance debugging, which provide helpful context. That said, for this particular store—which is showing persistently higher TTFB—we’re looking to go deeper. Are there any advanced tools, diagnostic techniques, or internal metrics (e.g., render timelines, partial caching behavior, app injection traceability) you’d recommend to help us more precisely identify and address performance bottlenecks?

Any additional insights or best practices you can share would be greatly appreciated.

Thanks in advance for your support!

4 Likes
2

Dear Shopify,

Just wanted to echo Michał’s question. We’d love to better understand how we can focus more on improving TTFB scores. Any advice you can provide during the AMA is very much appreciated.

Warmest regards,

Thomas

3

Hello and thanks for your question!

You can use our Shopify Theme Inspector Chrome extension to identify what might be causing slow Time to First Byte (TTFB) scores. Once installed, you can sign in with your Shopify credentials and access a “Shopify” panel in Chrome DevTools.

To use it, open Chrome DevTools, navigate to the Shopify tab, and click the reload icon. This will reload the page and display a flame chart with clear and readable information about the Liquid code executed to generate the HTML response. When TTFB is slow, you can identify potential loops or snippets that may be causing delays.

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Regarding caching, Shopify does not send any Cache-Control header for HTML documents or cache them in our CDN (Cloudflare) because they are considered dynamic content.

I hope this helps you identify and address potential TTFB issues!