Does Hotjar Slow Down My Site?

Yes, Hotjar can slow down your site. This slowdown largely depends on how Hotjar is implemented; however - optimizations like asynchronous loading, sampling, image compression, and CDN usage can help mitigate potential performance impacts and keep any speed reductions to a minimum while providing important user behavior insights.

At Deepbux, we aim to help website owners increase conversion rates by providing tools to track, analyze, and engage visitors. We understand owners need insights to optimize the user experience without compromising site performance. Any additional JavaScript can potentially slow down a site. Many of our customers utilize services like Hotjar, which research shows can slow load times. Seeing this firsthand in working with clients, we decided to dive into how much of an impact Hotjar has on site speeds. 

In this article, we seek to address those concerns by examining exactly how Hotjar works and its potential effects on performance. 

How Does Hotjar Work?

Hotjar is a user experience analytics tool that allows companies to visualize how visitors engage with a website. It works by injecting a small snippet of JavaScript into the pages it is tracking. This script then watches for DOM changes and user interactions like clicks, scrolls, and hovers. When these events occur, Hotjar logs the associated data, which can later be viewed in its dashboard. 

Hotjar's tracking script is designed to have minimal impact on site speed, which is important for user experience and search engine optimization. The script loads asynchronously in two parts - the first contains Hotjar's configuration settings for that particular site. Loading asynchronously means the script does not block or delay other page assets from loading. However, any additional JavaScript, no matter how small, will have some effect on performance. According to our research, Hotjar adds approximately 500 milliseconds to average page load times.

Hotjar loads its tracking code asynchronously to avoid blocking the loading of other page elements. This allows the main HTML, CSS, JavaScript, and other assets to load initially without delay. Then, the Hotjar script loads in the background without interrupting the user experience. As a data company, this approach aligned with one of our principles of prioritizing site speed.

How Does Hotjar Affect Site Performance?

We understand the importance of analyzing user behavior to improve our services. Tools like Hotjar allow us to visualize how visitors interact with our website. This provides valuable insights to enhance the user experience. Hotjar allows us to visualize how visitors interact with our website. 

However, we also recognize that every additional script has the potential to impact site speed. Some key things to understand about Hotjar’s performance on sites:

• Every piece of JavaScript, including Hotjar's tracking code, uses system resources that could slow a page down. However, Hotjar is designed to have minimal impact as it only collects data in modern browsers that efficiently execute code.
• Still, some users report more significant slowdowns after installing Hotjar. One study found it increased load times by almost a second on average. With Google recommending pages load within 2 seconds, this is worth noting. 
• Hotjar's recordings and heatmap tracking capture cursor position, scroll position, and clicks every 100ms (10 times per second) in supported browsers using efficient APIs. This frequent, lightweight collection aims to have low overhead and operates seamlessly on modern browsers.
• Data collection starts when the Hotjar code loads and isn't manually started/stopped. It tracks across all pages with the code to get a full picture of journeys.
• Mutations to the page, like clicks, are captured using the built-in MutationObserver API. This integrates the tracking directly into events already happening rather than adding extra processing.

To strike a balance, we carefully consider Hotjar's potential impact versus the insights we gain. We also work to optimize our site performance through techniques like code optimization, image compression, and cache configuration. This helps ensure tools like Hotjar don't negatively affect our users' experience.

The Impact of Hotjar on Site Speed

Hotjar itself states that its tracking code is meant to have minimal effect on performance, as recordings and heatmaps only function for modern browsers that can efficiently handle JavaScript. However, some reports have shown Hotjar adding up to half a second of load time according to metrics tools. On the upper end, one source estimated an increase of 500 milliseconds from Hotjar alone. 

Tool

Impact on Site Speed

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Hotjar

829 ms

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Mouseflow

68 ms

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Crazyegg

124 ms

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Deepbux

00 ms

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When compared to alternatives, Hotjar appears to have a more pronounced impact on speed based on available data. Mouseflow and CrazyEgg, two other popular options, have been observed to carry less of a performance penalty. Of course, every site is unique and speed can vary depending on other optimization factors as well.

HotJar vs Deepbux

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How To Reduce The Impact of Hotjar on Site Speed

For businesses that rely on tools like Hotjar for user behavior insights, it is important to understand ways to minimize any potential slowdowns these services may cause. Deepbux.io has identified several effective approaches based on best practices.

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• Use deepbux.io with its lightweight tracking code and low impact on speed.
• Use Hotjar's sampling feature to record a subset of visitors rather than all traffic, reducing the tracking load.
• Optimize website images by keeping file sizes small, so they load quickly and help offset other demands on bandwidth. 
• Leverage Hotjar's asynchronous loading option to prevent the tracking script from blocking other page elements and improve load times.  
• Take advantage of Hotjar's global CDN for faster, geographically distributed access to its code through proper CDN implementation.
• Time when Hotjar initializes by using Google Tag Manager's built-in timer or delaying startup until after the initial user interaction, like a click or scroll, to prevent slowing the initial page view.
• Consider Hotjar's free plan limitations if the pro version's more advanced features aren't necessary; the free option has a lighter resource impact.
• Monitor site speed with a tool like Google PageSpeed Insights both before and after making Hotjar implementation changes to ensure the desired impact reduction was achieved.
• Contact Hotjar support if further optimization is needed as they continue enhancing the tool's performance characteristics based on customer feedback.

For most businesses, the trade-off of a fractional speed decrease is likely worthwhile compared to gaining visibility into the user experience. Hotjar's data drives improvements that increase conversions and long-term performance. With the right setup and ongoing optimization, the tool's benefits can far outweigh initial page load times costs.

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Conclusion

While Hotjar provides valuable insights into user behavior and experiences on a website, it is important to consider its potential effects on performance. As discussed, Hotjar's tracking script introduces additional HTTP requests and JavaScript processing that can modestly increase page load times. However, with proper configuration, Hotjar leverages techniques like asynchronous loading and CDNs that help minimize these impacts. 

Ultimately, the benefits of Hotjar must be weighed against the potential costs to site speed. Hotjar imposes negligible slowdowns for most modern websites, especially when its features are optimized. The user experience insights gained often justify minor reductions in performance. Provided a site also prioritizes ongoing speed optimization, Hotjar need not negatively impact the user. Its detailed behavioral analytics, in turn, can help enhance conversions, reduce bounce rates, and improve overall experiences on the site. 

In these ways, Hotjar remains well worth considering as an important tool for any business seeking to understand better and serve their online users.

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