Merchants often use performance tools to analyze their site’s page load time to get an understanding of their shopper’s experience. These tools may occasionally list Bolt as a significant contributor to JavaScripts loading times. The following information is meant to help contextualize this perceived impact and assure you that Bolt is prioritizing, and will continue to prioritize, the speed of our services and the experience of your shoppers.
Performance tools provide insights into a site’s overall performance, but they do not convey the shopper’s dynamic experience of a site. Bolt’s javascript is loaded asynchronously, meaning after the web page renders. Bolt’s scripts do not affect metrics such as First Contentful Paint or Largest Contentful Paint, key metrics for SEO and reduced friction.
You can review Bolt’s load times on your store, using a Chrome browser, by doing the following:
that Bolt’s assets typically do not come before more critical assets needed to parse the page, as they are closer to (or after) the blue line.
You can verify this more specifically by inspecting an asset’s waterfall timeframe and checking when the item was queued. In the below example, Bolt’s connect.js script wasn’t queued until after the first 1.75 seconds had passed – deferring priority to assets that directly impact shoppers.
Bolt uses industry-standard caching procedures. This means that components will be cached on the browser for subsequent page visits. This prevents the re-loading of scripts and components and thus avoids adding delays.
The Initial script that triggers preloading, connect.js is small, about 200KB. The average for modern JS scripts is between 300KB - 400KB.