If you exceed your daily session capture limit, Hotjar will sample your traffic. Our sampling algorithm captures data at an even rate and ensures even distribution over time to give a more holistic view of visitor behavior.
- How to understand sampling
- What does the traffic coverage widget show?
- What if I adjust my session targeting and tracking settings?
- What is the difference between sessions and pageviews?
When talking about sampling, it helps to think about your site traffic being split into three categories:
- Total traffic - All visits to your website.
- Potential traffic - Visits to your website that Hotjar has the capability to track. To learn more about why some visits cannot be tracked, check out Does Hotjar track all your users?
- Sampled traffic - Visits that Hotjar is actively tracking on your website.
Sampling is done to ensure that your daily tracking limits are evenly distributed throughout each day.
If you have a plan with 500 daily sessions but you actually receive a higher number of daily users visiting your site, Hotjar will sample your traffic. This means that we'll capture an even number of sessions (500) spread throughout the day. This avoids 500 sessions being captured by midday and subsequently no sessions being captured during the remainder of the day.
Hotjar adjusts the flow of sessions based on the total number of sessions recorded over a moving 24-hour window. This gives you an even distribution of session capture throughout the day. This illustration compares static data capture and distributed session capture:
Notice how data capture is spread throughout the day, ensuring that you don’t miss data collection from sessions that occur later in the day. More information on what a session is can be found in What is a Session?
If the daily number of user visits (traffic) to your site exceeds the number of sessions in your Hotjar plan, Hotjar will capture a portion of your traffic. The traffic coverage widget shows this as a percentage of your traffic and is calculated by this formula:
Traffic coverage = Plan Daily Limit / Potential Traffic*
For example, if you have a Hotjar plan with 500 sessions, but your site has 1,000 sessions per day, then your traffic coverage would be 50%.
If you ever need to know whether your current plan is big enough to cover your site traffic, you can check whether your traffic coverage includes all of the potential traffic Hotjar could track.
Find the traffic coverage widget on the top right corner of insights.
Click on the button to show a more detailed breakdown of your traffic coverage.
If you'd like to learn more about what Hotjar can track as potential traffic, you can read more in our article Does Hotjar track all your users?
Admin users have the option to configure session targeting and tracking settings in Hotjar. As shown below, you can tell Hotjar to start collecting session data when a user visits a page or triggers an event that you have specified.
In the above example, Hotjar will start tracking a user session if a user visits either https://www.example.com or https://www.example.com/blog.
This allows you to limit the number of sessions that Hotjar captures, based on the pages that are of most interest to you.
Session capture will start when a user lands on a page specified, but other pages across the site that the user visits during that session will also be recorded. For more information on when a session begins and ends, see What is a Session?
Session targeting and tracking settings will impact sampling and the traffic coverage widget in different ways
If Hotjar is sampling your site’s traffic, the sample will be taken from the sessions that are being collected based on the configuration that is in place in the session targeting and tracking settings. Hotjar will not sample from all of your site’s traffic in this case - only from sessions that qualify based on your settings.
The traffic coverage widget you see in your dashboard, however, is not influenced by session targeting and tracking settings. Traffic coverage is always based on potential traffic for the entire site - it ignores any targeting rules you might apply in site settings. In other words, it always looks at all traffic you could be capturing with Hotjar across all pages.
In summary, sampling is entirely based on the number of sessions captured over time. Restricting targeting rules means that Hotjar will only record on a subset of pages. Sampling will start to let more sessions in so you still fulfill your daily plan limit to compensate for restricting targeting rules.
As long as you have enough traffic given your targeting rules, sampling will help you fulfill your daily limit.
Sampling works in different ways for session-based capture (Recordings and Continuous Heatmaps) and pageview-based capture (Manual Heatmaps).
If your Hotjar plan has a lower daily session/pageview limit than the number of visitors to your site, Hotjar will sample your traffic. The sample will be taken from all pages across your site where the Hotjar tracking code loads.
With session-based capture, you can adjust the session targeting and tracking settings within your Site Settings to limit the pages where sessions are captured.
For Manual Heatmaps (pageview-based), there isn't a way to limit or target specific pages to minimize sampling. The only way to achieve this would be to load the tracking code on a subset of pages where you want to collect Heatmap data.
Session-based capture and pageview-based capture have different underlying algorithms, and Manual Heatmaps will be based on a sample of all your site traffic (not just what is included in the session targeting and tracking settings).
In summary, the Hotjar Basic plan, as well as Manual Heatmaps, uses our original data capture method of tracking pageviews. If you are on a Hotjar Business or Plus plan and you use both Continuous and Manual Heatmaps, sampling will happen separately for both session-based capture and pageview-based capture. They are not dependent on one another and use different underlying algorithms.