The Complete
Session Replay Guide

What is session replay?

Imagine sitting next to your users while they're browsing your website. That would be awesome, wouldn't it? You'd get to experience first-hand what kind of issues they run into, and you'd see the parts of your application they don't get and feel frustrated about.

Imagine now being able to move them aside when those problems arise and open up their browser's developer tools to make sense of what went wrong. Wouldn't that be incredible?

This is where session replay comes into play. It allows you to watch how your users navigate your web application and see what happened under the hood, so you can easily reproduce the situation if anything goes wrong.

Problems solved by session replay

Session replay tools can cater to many different areas within the same company, making picking the right alternative even harder.

• Want to check out how users are interacting with the new design update? Session replay got you covered!
• Trying to figure out why the app keeps crashing? Session replay can answer that question.
• Curious about how users are reacting with the newly released features? You guessed it, session replay can help out as well!

Let's look at some of the most common use cases where session replay tools can shine like no other.

Who is session replay useful for?

Session replay technology is so versatile that it provides value to different teams within an organization. That’s one of the reasons why there are so many session replay alternatives in the market. They each focus on different personas and use-cases. There is hardly any tool out there that encompasses all of them together. So make sure to have your internal user and its primary use-case in mind when picking your session replay tool.

How does session replay work?

Let’s shed some light on what happens behind the scenes when capturing and replaying a session recording. Some parts may be technical, but don't worry; it will all make sense.

What gets really captured inside session replays?

The collected data may differ from one session replay tool to another. Remember, these tools may target different personas in an organization and therefore address some use-cases but not others. That being said, the best tools should be able to capture the below elements:

• User behavior: We're talking clicks, mouse movements, scrolls, hesitations, and more. Are users scrolling over important messages? Or perhaps are there rage clicking on some buttons? This data is valuable for surfacing key frustrations.
• DOM mutations: When you visit a website, your browser downloads then assemble various elements, such as pictures, text and videos before rendering each and every page. The Document Object Model (DOM) acts as a translator between these elements and your browser, allowing the web pages to be assembled and rendered. Session replay tools detect when any of these elements get updated, and capture these mutations (changes) as part of the replay. DOM mutations are the essential ingredients for session recordings. They are the frames that make up the replay.
• DevToolsThese are tools provided by browsers that help developers reproduce all sorts of issues in their local testing environments. Things like network requests and payloads, JavaScript errors, logs, and the web application’s state amongst other things. Some replay tools do capture that technical data, for each and every user session, making debugging a breeze for developers.
• Web vitals:Monitoring the loading times of your web app, not just pages but also its various resources, can provide valuable insights into how your users experience your site. In addition, metrics such as memory and CPU utilization can be used to track crashes and fix slowdowns in your application. This makes session replay tools a key piece of your observability stack.
• Frustrations:Click rages, excessive scrolling or dead clicks are examples of user frustrations that session replay platforms can detect. Identifying them is the first step towards providing a better product experience to your users.
• Custom events: That covers downstream or upstream events in your application that you may need to log alongside every recorded session. Tracking custom events means you can synchronize those bits of data with your replays for a much richer context.
• Metadata:Additional information about a particular recording. Things like userIDs, segments, browser versions, country and more. Metadata is used to filter through the replays and aggregate data.
• Assets:Caching of certain assets like images, fonts or stylesheets is a vital aspect of any session replay platform. Imagine you record a session for your new website, and a couple of months down the line, you decide to give it a fresh new look. Now, if the assets weren't cached, the old recording would simply be broken as it cannot reference its previous stylesheets and fonts. That's why asset caching is so important as it ensures that your replay stays true to its original form, no matter how much time has passed.

Instead of recording video (which would be bandwidth-intensive), these tools capture event data that can later be reconstructed into a visual replay.

Data Processing

Once collected, the data goes through several processing steps:

• Compression to reduce data size
• Removal of sensitive information (based on your privacy settings)
• Indexing for searchability
• Association with other metrics and events

This processing ensures that the data is stored efficiently and can be quickly retrieved when needed.

Replay Reconstruction

When you view a session replay, the tool reconstructs the user's experience:

• Rebuilds the DOM as it appeared to the user
• Replays user interactions in sequence
• Animates cursor movements
• Shows form inputs and changes
• Displays technical data alongside the visual replay

This reconstruction provides a highly accurate representation of what the user experienced, allowing you to see your application through their eyes.

Integration with Other Tools

Most session replay tools can integrate with other systems in your tech stack:

• Error tracking tools like Sentry
• Analytics platforms like Google Analytics
• Customer support systems like Intercom or Zendesk
• CRM solutions like Salesforce

These integrations enhance the value of session replay by connecting user behavior with other business metrics and workflows.

Data privacy in session replay

Most session replay tools allow developers to have control on what gets recorded and what gets sanitized. Sanitized elements are not sent to the server. In fact, they never leave your user’s browser. Instead, they’re either masked (i.e. text replaced by asterisks and images by placeholders) or not tracked (the data is simply ignored).

For example, let's say the user profile page in your website contains personal information that must be sanitized, like address and phone number. The development team could mark these fields as "masked" to the tracker. With that, anytime a user visits the profile page, the tracker would sanitize those fields by replacing their content with asterisks. This results in a properly sanitized replay that still fully captures the user journey without revealing any Personal Identifiable Information (PII).

Compliance

If you have PII data, there are always internal privacy policies to follow and external regulations to comply with.

Internally imposed policies can range from security restrictions around the infrastructure all the way to the software you can install. When it comes to international regulation, the three most important ones are:

When it comes to external compliances, the three most important ones are:

• GDPR Applies when collecting data from EU citizens. GDPR also allows users to ask you to remove their data from your databases. This, of course, covers session replay data.
• HIPPA This one is specific to healthcare-related data. If you're collecting this sort of information on your users, you’re most likely already complying with it.
• CCPA Similar to GDPR but for residents of California in the United States.

If you're not part of the healthcare industry, and your website is globally accessible, chances are you have to comply with GDPR and CCPA. Adding a session replay tool into the mix might seem like an extra hoop to jump through. However, these tools solve data privacy concerns through sanitization and other fine-grained controls. Developers can tell the tracker what data to track and what to ignore. That way, PII is kept safe within your user’s browser and is not transmitted to the server.

Therefore, it's always important to review and understand how session replay tools can deal with personal data so you can abide by the regulations in place.

Data ownership and security

Even though the data is sanitized, who owns it? And how can you ensure it’s safely processed and stored? This may give headaches to many compliance and security teams.

While most of the tools come in the form of SaaS applications, some session replay solutions allow you to self-host their entire platform on your premises. That means you own the data, which also rests on your servers, therefore complying with your internal security and privacy policies.

This is a crucial point. Make sure you’re fully aware of the details when deciding which session replay platform to pick.

Session replay pricing

Understanding session replay pricing models helps you make informed decisions and avoid unexpected costs. Let's explore the common pricing structures and considerations.

Common Pricing Models

Session replay tools typically use one of these pricing models:

Hidden Costs to Consider

Beyond the base pricing, be aware of these potential additional costs:

• Storage duration: Longer retention periods often cost more
• Advanced features: Some tools charge extra for features like heatmaps or error tracking
• Integration costs: Connecting with other tools in your stack might incur fees
• Implementation support: Technical assistance during setup might be an additional cost
• Custom data retention: Special compliance requirements might affect pricing

Always ask about these potential costs during your evaluation process.

What to look for in a session replay tool

With many session replay tools on the market, choosing the right one for your needs can be challenging. Here's what to consider during your evaluation process.

Essential features

Ease of implementation

A session replay tracker should not require more than a few lines of code to get started, regardless of your tech stack. Once the basic setup is complete, you should look for how easy it is to extend its capabilities. The more flexibility the tool provides, the more likely it can fit within your use case.

An ideal tracker should be easy to set up with minimal code, but at the same time, it should give you all the options you need to customize it however you see fit. This includes capturing custom events, sanitizing data, adding extra information to sessions, and more. All of this should be accomplished while minimizing performance impact.

Powerful DevTools

To leverage the power of session replay for your frontend developers, it's important to provide an environment that closely resembles what they already know and use on a daily basis. In fact, every major browser comes with some variation of DevTools, a set of technical tools that help developers, in their day-to-day job, reproduce and debug all sorts of issues.

An ideal session replay tool should be able to capture those technical clues and provide a familiar debugging experience to developers. After all, one of the areas where session replay is especially effective is in reducing the time required to identify and fix bugs.

Self-hosting

As discussed in the Data Privacy section, compliance and security policies may not give you the choice as whether to host the session replay platform or use it as a cloud service.

Fortunately, certain session replay solutions offer a self-hosting option that allows you to install and operate their entire platform on your own servers. This provides two major benefits:

• Full control over the data generated by your users. Session replay data goes directly to your servers, where it’s processed and stored.
• Compliance with internal policies and regulationbecomes much easier this way. No more time is wasted on lengthy compliance and security checks.

Extensibility

Developers enjoy tweaking, enhancing, and building custom features on top of their session replay tool. An open-core or plugin-based architecture makes a solution extensible by design and future-proof for internal user needs.

If you prioritize extensibility and customization, consider exploring open-source session replay solutions when evaluating alternatives.

Search capabilities

Capturing millions of sessions per day can make finding the relevant replay feel like searching for a needle in a haystack. An ideal session replay tool should offer a powerful and versatile search engine. This requires the ability to filter by almost any captured piece of data, such as a user action, a particular session attribute, or a technical event.

Such filtering capabilities become critical to choosing the right tool.

Analytics

It’s not far-fetched to think that with all the data captured by session replay tools, one could create various visualizations to track and understand different aspects of the web app.

For instance, you can create a dashboard to monitor your website's performance, including loading times, slowest resources, and other web vital metrics. You can also receive alerts when something goes wrong and use session replay to identify the root cause. This reduces the time to resolve potentially critical issues.

So when choosing a session replay tool, prioritize the ability to aggregate data and create visualizations for the metrics that matter to you.

Pricing scalability

As mentioned in a previous section, there are two main pricing models for session replay solutions. When choosing a model, it is important to consider how scalable it is based on your website traffic and use case.

If your website generates millions of monthly sessions, consider a value-based pricing model. However, if you have low traffic, the cheapest alternative would be to use a session replay solution that offers volume-based pricing. Even better, look for open-source alternatives that you can host yourself to reduce costs.

Integrations

The ability to integrate with third-party tools is typically the hallmark of powerful session replay solutions. In fact, session replay shows you one side of the story: your frontend. What if you need the full context when reproducing a bug and therefore require backend logs? This is where integrating with other tools in your stack may be very helpful.

Another interesting type of integration is with ticketing systems, such as JIRA. By creating a ticket that includes all necessary details while reviewing a particular replay, you can significantly improve the workflow of your QA team.

So make sure to look for the available integrations when picking your session replay tool.

Breadth of features

While it is essential to ensure the solution you pick comes with the right set of features you need for your primary use case, it's actually recommended to keep an eye on all features the tool might have.

As stated previously, session replay tools can benefit various roles and teams within an organization. Although they may primarily target a few use cases, consider the tool that offers complementary features other team members could benefit from in the future.

Community

Finally, when deciding which session replay solution to choose, we believe it's important to consider its community. An active community, where users (or developers in the case of open-source products) are engaged and contributing to the platform, is a sign of a successful and healthy product.

Conclusion

Session replay tools have become essential for organizations focused on delivering exceptional digital experiences. By providing both visual context and technical data, they offer unique insights that other analytics tools simply can't match.

Whether you're a developer trying to fix elusive bugs, a product manager seeking to improve user flows, or a support team member helping confused customers, session replay can transform how you understand and optimize your web application.

As you evaluate options for your organization, remember to balance functionality with privacy considerations, and choose a solution that aligns with your specific needs and resources.