The Google tag, Meta Pixel, and Klaviyo, the three scripts found most often on Shopify storefronts, each put between 300 milliseconds and a full second of extra processing on an average store’s homepage when loaded on a mid-range phone, according to an index from Charleston ecommerce consultancy 2 Visions. The Google tag turned up on 547 of the 605 stores tested and landed in that heavy range on 75% of them, Meta Pixel showed up on 509 and was heavy on 70%, and Klaviyo appeared on 496. Yates Jarvis, the firm’s founder, said several of the costliest of the 116 apps measured handle work a store can’t drop, such as blocking fraud or winning back customers, so their weight has to be judged against what they bring in.






