Does Klarna slow down a store?
In 7IT’s test of 367 US online stores, Klarna ran on 26 of them (7.1%). On the median store that loads it, it downloaded 210 KB and kept the phone busy for 0.06 s before the page could respond.
7.1%of 367 US stores run it
210 KBmedian download on stores that load it
0.06 smedian time the phone spends running it
Stores with it and without it.
| Stores | Median score | Main content | Blocking time | Apps on the page | |
|---|---|---|---|---|---|
| With Klarna | 26 | 32 | 13.4 s | 1373 ms | 27 |
| Without | 341 | 34 | 11.5 s | 1241 ms | 19 |
Stores that run Klarna had a median score of 32, against 34 for stores without it. They also run more apps overall (a median of 27 against 19), so that gap is not all Klarna’s doing. The size and phone time above are Klarna’s own. On this sample there is no score penalty that can be pinned on it.
One in four stores that load it download more than 212 KB of it, and spend more than 0.08 s running it. Median Google phone-lab results, home pages only, September 2026. Method and limits in the study.
If you run Klarna.
- Pay-later messaging is useful on product and cart pages only. Load it there, after the price renders.