Answers about performance
Questions and answers from the Croct community about performance.
Coming off Optimizely on our headless storefront, does Croct avoid the render-blocking snippet?
our Hydrogen storefront has been running Optimizely and the snippet is a real cost. It loads synchronously on the critical path, and even with no experiment…
Does server-side fetchContent add a TTFB penalty on my Next app?
i moved our hero personalization out of a client hook and into a server fetchContent call in the App Router. my assumption was that the extra server-side…
Does resolving personalization server-side add a TTFB penalty?
evaluating croct and the one thing holding me back is TTFB. right now most of our pages are basically static, we sit around 180ms TTFB from origin and i do…
Keeping Oxygen's full-page cache while personalizing one hero section, is that possible?
Homepage on Hydrogen, served from Oxygen's full-page cache with CacheLong, hit rate is excellent and TTFB is around 40ms. Now the brief says personalize the…
Will content resolution hold up during Black Friday traffic, and what if it times out?
Preparing a Hydrogen store for Black Friday. Last year a client-side testing script fell over under load and blanked our hero for a chunk of the morning. Not…
What does personalization cost us in LCP on mobile?
80% of our traffic is mid-range Android. Current Lighthouse mobile: LCP 2.4s, TBT 190ms. With our previous client-side tool the anti-flicker snippet held the…
Nuxt + Storyblok variants swap in after hydration, did I wire this wrong?
I have a Nuxt 3 app rendering Storyblok blocks, with Croct added as a client-side plugin: Expected: personalized block is rendered directly. Actual: the…
Will adding personalization tank our Core Web Vitals scores?
We guard a 95+ Lighthouse performance score on our marketing site and I am protective of it. I have read the SpeedCurve criticism of anti-flicker snippets,…
Worth adding preconnect hints for cdn.croct.io and api.croct.io?
Doing a resource-hints pass on a client site. Lighthouse flags third-party origins without preconnect. Which hosts does the Croct SDK actually talk to, and…
Sharing before/after LCP numbers from moving off a client-side testing tool
I do web performance at a retailer in the Benelux. We finished migrating our experiments from VWO to server-side resolution with Croct last month and I…
Personalizing Sanity content without turning every GROQ query per-user and losing the CDN
Prototyped personalization by injecting user attributes into our GROQ queries. Result: Sanity CDN hit rate went from 96% to under 20% in two days. Obvious in…
How much main-thread time does Croct event tracking add per page?
I am profiling INP regressions caused by third-party tags. Our current trace shows long tasks attributed to two analytics vendors, and I want to know where…