Does Segment slow down a store?
In 7IT’s test of 367 US online stores, Segment ran on 21 of them (5.7%). On the median store that loads it, it downloaded 155 KB and kept the phone busy for 0.10 s before the page could respond.
5.7%of 367 US stores run it
155 KBmedian download on stores that load it
0.10 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 Segment | 21 | 28 | 15.1 s | 2252 ms | 29 |
| Without | 346 | 35 | 11.5 s | 1243 ms | 19 |
Stores that run Segment had a median score of 28, against 35 for stores without it. They also run more apps overall (a median of 29 against 19), so that gap is not all Segment’s doing. The size and phone time above are Segment’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 240 KB of it, and spend more than 0.19 s running it. Median Google phone-lab results, home pages only, September 2026. Method and limits in the study.
If you run Segment.
- Analytics should be the lightest thing on the page. Load it with async or defer and keep one tool, not three overlapping ones.
- If several analytics tools answer the same question, keep the one the team actually opens.