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What is real user monitoring? (RUM)

Lauren Bennett
RUM
25 February 2026 • 8 min read
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Real user monitoring is a type of performance monitoring that captures and analyzes data about users on a particular website or application. Learn more about RUM in this post.

You and your team invest a great deal of time, passion, and energy in creating solutions that improve people’s lives. But no matter how carefully you code, real-life users and device environments are highly complex and unpredictable. It’s hard to be sure your work will always deliver the intended experience once you release it into the wild.

Real user monitoring (RUM) provides direct visibility into your user experience, allowing you to identify errors and improve user pain points.

Read on to discover the advantages and constraints of real user monitoring, along with how mobile user experience monitoring can enhance the enjoyment of your mobile users.

What is real user monitoring? RUM explained

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Real user monitoring, also known as RUM or end-user monitoring, is a form of passive application performance monitoring (APM). Not to be confused with mobile real user experience monitoring (MRUM), RUM enables you to collect and analyze data about every user interaction within your service or software.

Unlike traditional APM tools that focus on system-level metrics and logs, RUM monitors the entirety of how real users actually engage with your platform.

It covers metrics such as Time to First Byte (TTFB), Page Load Time, and Interaction to Next Paint (INP), among others.

In simple words, real user monitoring (RUM) is a way for you to see how actual people, not just test users in made-up scenarios, experience your website or app.

Why do you need real user monitoring?

Understanding how users behave when using your app or website in the real world lets you actively improve your user experience before the issues impact your business.

It provides visibility into how users interact with your product and how effectively the software responds to each user action and network request.

Such detailed user-centric insights allow your team to measure performance, optimize user journeys, and ultimately create a more dynamic, reliable, and responsive experience.

RUM is versatile and can be used on various platforms and apps. Although for phones and tablets, Mobile RUM can provide more in-depth analyses specifically tailored to those devices.

What is the difference between synthetic monitoring and real user monitoring?

Synthetic monitoring and real user monitoring (RUM) are both used to measure application performance, but they serve different purposes and answer different questions.

Synthetic monitoring uses scripted tests (often called “synthetics” or “robots”) to simulate user interactions with an application. These tests run on a schedule from predefined locations and follow a fixed path, such as loading a page, submitting a form, or completing a checkout flow. Synthetic monitoring is useful for proactively testing availability, validating performance during deployments, and detecting issues before real users encounter them.

Real user monitoring, on the other hand, collects data from actual users as they interact with your website or application in production. Rather than simulating behavior, RUM captures real-world performance metrics, errors, and user interactions across different devices, browsers, locations, and network conditions. This makes it especially valuable for understanding how performance issues affect real users and business outcomes.

How does real user monitoring work?

Since RUM is most commonly associated with web monitoring, we’ll use this for our explanation.

You begin the process by adding a lightweight JavaScript agent to your website. This agent runs in the user’s browser to passively collect performance, network, and interaction data, without affecting the user experience.

The code can measure everything from page load times to DNS delays and send the data back to a server for analysis. You can use it to examine how your website or app behaves inside the browser and identify database or server errors.

An optimal RUM solution should be fine-grained enough to let you spot exactly where your users might be experiencing friction. It should let you observe every step of a user’s journey from first touch to payment or show you what happened before they decided to quit a session.

The solution should also be able to highlight differences in user experiences according to different user conditions, like geographic location, device type, or network conditions. For example, you might discover that many users in Germany are experiencing unexpected time-outs when trying to connect to your servers. RUM data is valuable in helping you optimize your UX and ensure that applications meet the expectations of real-world customers, no matter where they are.

Real user monitoring captures a broad set of performance and experience metrics based on how real users interact with an application in production. These metrics can be grouped into several key categories, each offering insight into a different aspect of the user experience.

Performance and loading metrics

These metrics help teams understand how quickly an application becomes usable and responsive for real users.

  • Page or screen load time — Measures how long it takes for a page or app screen to load and become interactive. Slow load times are a common cause of user frustration and abandonment.
  • Time to first byte (TTFB) — Indicates how long it takes for the browser or app to receive the first response from the server after making a request, helping identify backend or network latency.
  • Core Web Vitals (web) — Metrics such as Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS) quantify perceived performance, responsiveness, and visual stability in real browser sessions.

Interaction and responsiveness metrics

These metrics focus on how the application responds to user input and interactions.

  • Input delay and interaction latency — Measures the delay between a user action (click, tap, scroll) and the application’s response, highlighting sluggish or blocked UI interactions.
  • Long tasks (web) — Identifies JavaScript tasks that block the main thread and prevent the UI from responding quickly to user input.
  • UI responsiveness (mobile) — Tracks frame drops, slow rendering, or unresponsive UI states that degrade the mobile user experience.

Reliability and error metrics 

These metrics reveal stability issues that directly impact user trust and satisfaction.

  • JavaScript and frontend errors — Captures uncaught exceptions, runtime errors, and other frontend failures that may break functionality or degrade experience.
  • Network and API error rates — Tracks failed or slow network requests, including timeouts and server errors, that interrupt user workflows.
  • Crash rates and ANRs (mobile) — For mobile apps, monitors application crashes and Application Not Responding (ANR) events, which are among the strongest indicators of poor user experience.

User behavior and session metrics

These metrics help teams connect technical performance to real user behavior and business outcomes.

  • Session duration — Measures how long users remain active within an application, offering signals about engagement and usability.
  • User flows and navigation paths — Shows how users move through pages or screens, making it easier to identify friction points and drop-offs.
  • Bounce and exit rates — Highlights where users leave the application, often due to performance issues or unexpected errors.

Environment and context metrics

These metrics provide the context needed to understand why issues occur under certain conditions.

  • Device and browser type — Breaks down performance by device model, operating system, and browser version.
  • Geographic location — Reveals regional performance differences caused by network latency or backend configuration.
  • Network conditions — Tracks performance across Wi-Fi, cellular, and varying connection speeds, which is especially important for mobile users.

By analyzing these categories together, real user monitoring helps teams understand not just what is slow or broken, but who is affected, under what conditions, and how it impacts the overall user experience

Real user monitoring examples

Many companies leverage the benefits of RUM to improve their online performance across platforms. Three commonly used RUM tools are:

  1. Datadog — Datadog’s RUM solution provides real-time monitoring of the activity and experience of web and mobile app users. Among other things, it allows you to track frontend performance, network requests, and user journeys, monitor and track bugs and errors, and access all user session information.
  2. Dynatrace — This cloud-based RUM platform covers various aspects of application performance. Dynatrace offers full-stack monitoring, including frontend, backend, and infrastructure monitoring.
  3. New Relic — New Relic includes tools to compare your web metrics to industry standards, monitor global performance, track error rates, and identify adverse user interactions.

What is the benefit of real user monitoring?

Let’s take a closer look at how RUM improves the user experience.

  1. Performance optimization — With data on user interactions, you can spot bottlenecks and rectify issues such as poor load times or platform sluggishness before they affect more users.
  2. User-centric insights — Capturing data on behaviors and preferences allows you to better tailor your digital offerings to meet user expectations.
  3. Error detection and reporting — RUM can swiftly identify and report errors like memory leaks, resource exhaustion, and ANRs (Application Not Responding), enabling prompt resolution for a smoother online experience.
  4. Conversion rate improvement — By analyzing user interactions, RUM helps engineers eliminate friction points and enhance the effectiveness of digital strategies to increase conversion rates and reduce churn.

What are the limitations of RUM?

Despite its advantages, RUM is not an all-encompassing solution. The vast quantities of data RUM generates can lead to overload. This may obscure crucial performance patterns and hinder your ability to focus on key metrics. Unless you use a mobile user experience monitoring (MUEM) tool like Embrace, you may need additional software to sift through data efficiently, visualize it, and extract meaningful insights.

RUM is most effective when it captures 100% of user session data. However, not all RUM solutions offer this, and those that do often charge extra for different elements of data ingest, such as logs, spans, and traces. Therefore, scaling up these solutions can become extremely expensive.

If you’re in the mobile space, one way to overcome this limitation is to use a mobile user experience monitoring (MUEM) platform that offers transparent pricing based on sessions.

The future of real user monitoring

It doesn’t take a crystal ball to know that mobile is the future of all things digital. That said, while mobile undoubtedly means bigger audiences, it also presents unique challenges to application monitoring and far more scrutiny from users.

Mobile users don’t just expect fast and painless experiences — they demand it. Whether they encounter slow loading, bugs, or unresponsive features, the slightest friction on their customer journey can send them elsewhere.

Monitoring solutions that were built for the web and backend were never meant to address the needs of today’s mobile engineers. And in this case, leveraging the wrong tools often leads to blind spots that impact your users, hurt retention, and limit growth.

RUM has its use cases, but its limitations mean it is only one part of effective mobile user experience monitoring. When mobile is a priority, as it is today, your company needs a powerful mobile user experience monitoring solution that lets you see exactly what your customers are experiencing and where your issues lie.

What is mobile user experience monitoring from Embrace?

While RUM mainly relies on capturing individual events, mobile user experience monitoring gives you complete technical and behavioral details for every user session.

When mobile user experience monitoring is integrated into your application, it allows you to fully understand the internal states of your app and find the root cause of issues by analyzing its external outputs.

Embrace is the only tool specifically built for mobile user experience monitoring and can provide 100% of the data from 100% of mobile user sessions. It allows you to rapidly identify, triage, and solve errors, ensuring that every click, scroll, and tap contributes to a satisfying user journey.

Wildlife improves their mobile app performance with Embrace

Wildlife, one of the largest mobile gaming companies in the world, uses Embrace to gain deeper and more reliable insights into how users interact with its apps. The company has been able to anticipate issues before they affect players, understand and reduce ANR rates, discover previously undetected crashes, identify false positives, improve retention, and increase daily active users.

Read the case study

To create the best mobile app, your mobile user experience monitoring solution should offer:

  • 100% data capture for every user session — Embrace allows you to recreate every user journey within and across sessions by capturing detailed technical and behavioral data such as vitals, screens, taps, network calls, crashes, push notifications, and more.
  • Full-context error tracking — With full-context error tracking, you can explore the connection between errors and key activities, such as network calls, connectivity switches, and UI events like taps or scrolls, to get to the root cause quicker. Errors are logged and filtered by key-value pairs, and crashes are automatically classified.
  • Better information management — You need a tool that  helps you proactively optimize your mobile performance by providing rich, contextualized, actionable data, custom dashboards, and advanced filtering. Real-time, interactive visualizations allow you to instantly identify why a session was interrupted.
  • Configurable alerts — You need to be able to define which metrics, errors, user segments, or properties to monitor and configure highly targeted alerts for your app.

Want to learn more about mobile user experience monitoring and see how Embrace can give you deeper insight to identify and solve your toughest user-impacting issues? Request a demo today.

Embrace Wildlife exceeds user expectations with Embrace

Learn more about how Embrace helps Wildlife understand user issues, gain deeper insight into every session, and improve app performance with data-driven mobile tooling.

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Author
Lauren Bennett
Lauren Bennett
Lauren Bennett is a technical content writer at Embrace. She brings over seven years of experience in marketing and content writing to the team, with previous experience in editorial, marketing, and technical writing across a variety of industries.
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