Same-store LCP and Core Web Vitals change, October to November 2025
| Platform | Stores | 5%+ slower LCP | Oct passers failing in Nov | Pass rate Oct | Pass rate Nov | Median LCP change |
|---|---|---|---|---|---|---|
| Shopify | 36,117 | 20.9% | 7.5% | 52.3% | 53.5% | -22 ms |
| WooCommerce | 20,383 | 25.1% | 10.1% | 31.9% | 32.5% | -18 ms |
| Magento | 7,969 | 20.3% | 7.1% | 37.3% | 39.1% | -45 ms |
| All stores | 64,469 | 22.1% | 8.1% | 44.0% | 45.1% | -24 ms |
Source: PageSpeed Matters, Nov 2025. HTTP Archive top 1M with CrUX LCP in both months.
Summary
November is the busiest month of the year for most online stores, and it is also when stores add banners, sale widgets and campaign scripts. We wanted to know whether stores actually get slower for real shoppers over Black Friday, or whether that is mostly a worry.
The answer is both. Comparing the same 64,469 stores in October and November 2025, 22.1% had a Largest Contentful Paint (LCP) at least 5% slower in November. But the median store did not slow down at all: its LCP changed by -24 ms. A sizeable minority of stores slowed while the typical store held steady.
What we measured
We used the HTTP Archive monthly crawls for October and November 2025 and compared each store with itself. Stores here means Shopify, WooCommerce and Magento sites in the top 1M with Chrome UX Report (CrUX) LCP data in both months. That gave 64,469 stores: 36,117 on Shopify, 20,383 on WooCommerce and 7,969 on Magento.
All figures are CrUX field data at the 75th percentile, from real Chrome users. A store "slowed" if its November LCP was 5% or more above its October LCP. A store passes Core Web Vitals when its loading, responsiveness and visual stability metrics are all rated good.
One limit matters. Monthly field data covers the whole of November, so the Black Friday week is averaged in with the rest of the month. The real Black Friday effect on any single store may be sharper than these month-to-month numbers show.
One in five stores slowed, but the median store did not
22.1% of the 64,469 stores had a 5% or more slower LCP in November than in October. Among the 28,348 stores that passed Core Web Vitals in October, 8.1% failed in November.
The typical store did not slow down. The median LCP change was -24 ms, and 53.7% of stores got at least 10 ms faster between the two months. So the season does not drag every store down. It is more accurate to say a minority of stores slow down noticeably while most stay flat or improve.
One likely reason for the split is that stores handle the season differently, though this data does not show what each store changed. Some add popups, countdown banners and campaign scripts for the sale, while others freeze changes before the busy period.
22.1%
Share of 64,469 Shopify, WooCommerce and Magento stores whose LCP was 5% or more slower in November 2025 than in October.
Pass rates edged up overall
Across all stores, the Core Web Vitals pass rate edged up from 44.0% in October to 45.1% in November. That is because movement went both ways: 8.3% of stores that failed in October started passing in November, slightly more than the 8.1% of October passers that dropped out.
Every platform followed this pattern. Shopify went from 52.3% to 53.5%, WooCommerce from 31.9% to 32.5% and Magento from 37.3% to 39.1%. The overall gains are small, and the stores that dropped out are the ones that matter most to their owners, because they lost a passing status in their busiest month.
WooCommerce stores slowed most often
WooCommerce stores were the most likely to slow down. 25.1% of 20,383 WooCommerce stores had a 5% or more slower November LCP, against 20.9% of 36,117 Shopify stores and 20.3% of 7,969 Magento stores.
The same holds for losing a passing score. 10.1% of the 6,500 WooCommerce stores that passed Core Web Vitals in October failed in November, against 7.5% on Shopify (of 18,878) and 7.1% on Magento (of 2,970).
The median store on every platform still got slightly faster. The median Magento store improved most (-45 ms), followed by Shopify (-22 ms), and the median WooCommerce store least (-18 ms). WooCommerce stores often run on their own hosting, so extra traffic and new plugins may show up as slower loading more readily than on a hosted platform. That is a possible reason, not something this data proves.
Popular stores held up a little better
Stores with more traffic slowed slightly less often. 19.5% of the 2,432 stores in the Top 100K slowed by 5% or more, against 22.2% of the 62,037 stores in the rest of the top 1M.
The gap is modest. Larger stores tend to have development teams, staging environments and change freezes before the holidays, which may explain some of it.
What this means for your store
If your store is one of the one in five that slows down in November, you lose speed exactly when traffic and revenue peak. Much of that risk can be planned for.
- Set a change freeze. Finish theme changes and new apps by October, and test them before the sale traffic arrives.
- Plan sale features in advance. Banners, popups and countdown widgets should be added, tested and measured before Black Friday, not on the day.
- Check field data, not just lab tests. Watch your CrUX LCP in PageSpeed Insights or Search Console through October and November, keeping in mind the 28-day window.
- Remove campaign scripts afterwards. Take out sale widgets and tracking tags once the campaign ends so they do not stay on the site all year.
- On WooCommerce, check hosting and plugins. Confirm your hosting can handle peak traffic and that page caching still works on the pages you promote.
Sources
- HTTP Archive monthly crawls, October and November 2025, top 1M sites
- Chrome UX Report (CrUX), 75th percentile field data, October and November 2025
- Chrome UX Report documentation, Google: https://developer.chrome.com/docs/crux
Frequently asked questions
Do online stores get slower on Black Friday?
Some do. 22.1% of 64,469 stores had a 5% or more slower LCP in November 2025 than in October, but the median store got slightly faster, by 24 ms.
How many stores fail Core Web Vitals in November?
8.1% of the 28,348 stores that passed Core Web Vitals in October 2025 failed in November. Because 8.3% of failing stores started passing, the overall pass rate still edged up from 44.0% to 45.1%.
Which ecommerce platform slows down most over the holidays?
WooCommerce. 25.1% of WooCommerce stores had a 5% or more slower November LCP, against 20.9% on Shopify and 20.3% on Magento, and 10.1% of WooCommerce stores passing in October failed in November.
Holiday slowdowns are easier to prevent than to fix mid-sale, because most of the risky changes can be scheduled and tested ahead of time. Need help with this? See our ecommerce CRO agency.