Does Sentry slow down a store?
In 7IT’s test of 367 US online stores, Sentry ran on 45 of them (12.3%). At first load it is light: a median of 1 KB and 0.00 s of phone time. Google’s test measures the first load only, so anything it loads after a visitor interacts is not in these numbers.
Stores with it and without it.
| Stores | Median score | Main content | Blocking time | Apps on the page | |
|---|---|---|---|---|---|
| With Sentry | 45 | 31 | 10.6 s | 1971 ms | 26 |
| Without | 322 | 35 | 12 s | 1192 ms | 20 |
Stores that run Sentry had a median score of 31, against 35 for stores without it. They also run more apps overall (a median of 26 against 20), so that gap is not all Sentry’s doing. The size and phone time above are Sentry’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 3 KB of it, and spend more than 0.00 s running it. Median Google phone-lab results, home pages only, September 2026. Method and limits in the study.
If you run Sentry.
- Error monitoring should use the vendor’s lazy loader, so the full library downloads only when an error happens.