CWV pass rate with and without a session recording or heatmap tool
| Group | Pass with | Pass without | Median INP with | Median INP without | Homepages with tool |
|---|---|---|---|---|---|
| Top 10K | 31.8% | 51.6% | 226 ms | 158 ms | 1,093 |
| Ranks 10K to 100K | 31.3% | 44.3% | 210 ms | 166 ms | 10,330 |
| Rest of top 1M | 40.0% | 43.1% | 171 ms | 153 ms | 99,618 |
| WordPress | 39.5% | 50.6% | 154 ms | 125 ms | 15,369 |
| Shopify | 52.8% | 60.9% | 163 ms | 145 ms | 17,993 |
| Webflow | 39.4% | 55.1% | 170 ms | 128 ms | 879 |
| Other platforms | 34.9% | 40.3% | 184 ms | 165 ms | 76,674 |
| All homepages | 39.1% | 43.3% | 174 ms | 154 ms | 111,041 |
Source: PageSpeed Matters, HTTP Archive top 1M crawl and CrUX, Sept 2026. Homepages with tool counts all detections, including those without CrUX data.
Summary
Session recording and heatmap tools show site owners where visitors click, scroll and give up. They are a staple of conversion work, and many are free to install. They also run on every page view, watching the page as the visitor uses it.
We counted how many top 1M homepages load one and compared their Core Web Vitals with sites that do not. 111,041 of 782,850 homepages (14.2%) load a session recording or heatmap tool, and they pass Core Web Vitals 39.1% of the time against 43.3% without. The gap is wider among popular sites and holds on every major platform we checked.
What we measured
We used the HTTP Archive crawl of the top 1M sites from September 2026, on mobile, covering 782,850 homepages. A homepage counts as running a session recording or heatmap tool when the HTTP Archive crawl detects one of the common recording tools on it.
For speed, we joined homepages to Chrome UX Report (CrUX) field data at the 75th percentile. A site passes Core Web Vitals when loading, responsiveness and visual stability are all rated good. We also compared median Interaction to Next Paint (INP), the metric for how quickly a page responds to taps and clicks.
Popularity bands do not overlap: Top 10K, ranks 10K to 100K, and the rest of the top 1M. These results are correlations. They show which sites tend to pass, not what any single tool does to a page.
One in seven homepages run a recording tool
111,041 of 782,850 top 1M homepages, or 14.2%, load a session recording or heatmap tool. Those homepages pass Core Web Vitals 39.1% of the time, against 43.3% for homepages without one, and their median INP is 174 ms against 154 ms.
Adoption is flat across popularity. 14.6% of Top 10K homepages run one, 15.3% of ranks 10K to 100K and 14.1% of the rest. Platform matters far more: 38.2% of Shopify homepages run a recording tool, against 13.5% of WordPress homepages. Shopify's app store makes these tools a one-click install, which likely explains part of that lead.
By tool, Microsoft Clarity leads by a wide margin. It is on 83,792 homepages, followed by Hotjar on 26,434, Crazy Egg on 6,138, Contentsquare on 3,795 and FullStory on 1,607. Clarity is free to use, which likely helps its reach.
14.2%
Share of 782,850 top 1M homepages that load a session recording or heatmap tool.
The gap widens sharply among popular sites
The overall gap is modest, but it grows at the top. Top 10K homepages with a recording tool pass Core Web Vitals 31.8% of the time (956 with CrUX data), against 51.6% without (5,566). Their median INP is 226 ms, against 158 ms.
Ranks 10K to 100K show a similar pattern: 31.3% pass with a recording tool against 44.3% without, with a median INP of 210 ms against 166 ms. In the rest of the top 1M, the gap narrows to 40.0% against 43.1%.
Popular sites that record sessions likely run more of everything: more analytics, more testing tools and more marketing tags. Recording tools add their own work on top, because they track clicks, scrolls and changes to the page as they happen. The data cannot separate the two, but the INP gap is consistent with extra main-thread work on the sites that carry them.
The gap holds on every major platform
Comparing sites on the same platform keeps the gap in place. On WordPress, sites with a recording tool pass 39.5% of the time (13,851 with CrUX data) against 50.6% without (86,062). On Shopify, they pass 52.8% (17,420) against 60.9% (27,837).
Webflow shows the same pattern: homepages with a recording tool pass 39.4% (799) against 55.1% without (1,509). Sites on other platforms pass 34.9% with a recording tool against 40.3% without.
Median INP is higher with a recording tool on every platform in the table. On WordPress it is 154 ms against 125 ms, and on Shopify 163 ms against 145 ms. Unlike some other tool categories, the platform mix does not explain this one away.
What this means for your site
Session recordings are useful, but they are not free. Treat them as a research tool you switch on for a purpose, not a script that runs forever.
- Record a sample of sessions rather than every visit, if your tool supports sampling.
- Limit recording to the pages you are studying, such as product pages or checkout, instead of the whole site.
- Load the script after the page is interactive, not in the head.
- Run one recording tool, not two. Check for old tools that were never removed.
- Turn recording off when a research project ends, and watch your INP in Search Console's Core Web Vitals report before and after.
Sources
- HTTP Archive crawl of the top 1M sites, September 2026, mobile
- Chrome UX Report (CrUX) field data, 75th percentile, September 2026
- Interaction to Next Paint (INP), web.dev: https://web.dev/articles/inp
Frequently asked questions
How many websites use session recording tools?
14.2% of top 1M homepages, or 111,041 of 782,850, load a session recording or heatmap tool. On Shopify the share is 38.2%, against 13.5% on WordPress.
What is the most popular session recording tool?
Microsoft Clarity, on 83,792 top 1M homepages. Hotjar is on 26,434, Crazy Egg on 6,138, Contentsquare on 3,795 and FullStory on 1,607.
Do session recording tools slow down a website?
Sites that run them pass Core Web Vitals less often: 39.1% against 43.3% without, with a median INP of 174 ms against 154 ms. The gap appears on WordPress, Shopify and Webflow alike, though the data shows a link rather than a proven cause.
Recording tools can be sampled, scoped and loaded late, so you keep the insight without paying for it on every visit. Need help with this? See our conversion rate optimization agency.