Does Hotjar slow down a store?
In 7IT’s test of 367 US online stores, Hotjar ran on 39 of them (10.6%). On the median store that loads it, it downloaded 64 KB and kept the phone busy for 0.09 s before the page could respond.
10.6%of 367 US stores run it
64 KBmedian download on stores that load it
0.09 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 Hotjar | 39 | 32 | 10.5 s | 1971 ms | 28 |
| Without | 328 | 35 | 12.1 s | 1214 ms | 19 |
Stores that run Hotjar had a median score of 32, against 35 for stores without it. They also run more apps overall (a median of 28 against 19), so that gap is not all Hotjar’s doing. The size and phone time above are Hotjar’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 66 KB of it, and spend more than 0.13 s running it. Median Google phone-lab results, home pages only, September 2026. Method and limits in the study.
If you run Hotjar.
- Session replay and heatmaps record every visitor. Sample a share of sessions instead of all of them.
- Start recording after the page is idle, not during the first paint.
- Turn it off when the question you installed it for is answered.