7 Application Monitoring Tools to Catch Errors on the Frontend

default image

Building a quality web or mobile application is no easy feat these days. With users expecting seamless performance and minimal bugs, having robust monitoring in place is absolutely critical.

As an experienced developer, I know first-hand how vital application monitoring is, especially on the frontend where your users directly interact. Any hiccups here can destroy their experience and loyalty.

In this comprehensive guide, I‘ll explain why frontend monitoring matters, the common issues it helps detect, and 7 powerful tools to implement it effectively. By the end, you‘ll have the knowledge to pick the right solution for catching errors before they ruin your app and business. Let‘s dive in!

Why Frontend Monitoring is Essential

The frontend refers to the presentation layer of an application – the user interface (UI) code, visual elements, and client-side logic. It‘s what your users actually see and interact with.

Monitoring the frontend is crucial for several reasons:

  • It‘s complex – Modern web and mobile apps rely on intricate JavaScript frameworks like React, Angular, and Vue.js. Bugs can easily emerge.

  • It‘s dynamic – The frontend changes constantly, with frequent code updates, new features, and framework migrations. Errors get introduced if you‘re not watching carefully.

  • It‘s user-facing – Any frontend crashes or performance issues directly impact your customers. Bad app behavior means lost business.

  • It‘s distributed – Users access your frontend from diverse devices, browsers, locations, networks. You need visibility into how it performs across environments.

Simply put, frontend monitoring provides early warning for problems that damage user experience. It gives your team the ability to identify, diagnose, and resolve frontend errors before they ruin your app‘s reliability and your customer satisfaction.

According to research by Akamai, a 1 second delay in page load time can cause:

  • 16% loss in customer satisfaction
  • 7% loss in conversions
  • 11% fewer page views

Clearly, every millisecond matters on the frontend. Comprehensive monitoring is no longer optional. Let‘s explore what exactly it entails.

What Does Frontend Monitoring Involve?

Frontend monitoring encompasses tracking various types of issues that impact your users, including:

JavaScript Errors

Since most web and mobile apps rely heavily on JavaScript for interactivity, detecting JS errors is a top priority. For example, syntax errors from buggy code, unhandled promise rejections, and runtime exceptions.

Understanding JS error frequency, affected users, and stack traces helps prioritize which bugs to fix first.

Framework-Specific Issues

If you use popular frameworks like React, Angular, or Vue, the monitoring should be framework-aware and detect problems related to rendering, state management, routing, and more.

Network Request Failures

Apps make constant network calls to load data from APIs and other back-end services. Failed HTTP requests often break frontends, so tracking them is vital.

Performance Problems

Beyond errors, monitoring overall app performance metrics like page load times, request durations, and first paint provides optimization insights.

User Experience Issues

Watching real user sessions can reveal experience-breaking problems like rage clicks, infinite loops, confusing workflows, and more that impact engagement.

As you can see, comprehensive frontend monitoring provides tremendous value. It gives development teams the visibility they need into issues degrading app health, stability, and customer satisfaction.

Now let‘s look at seven excellent tools to achieve robust frontend monitoring.

7 Top Frontend Monitoring Tools


Sentry is an industry-leading error and crash reporting tool. It offers powerful frontend monitoring capabilities like:

  • Real-time error alerts – Get notified immediately of new frontend issues.

  • Contextual debugging – Sentry captures detailed context on each error like environment, stack trace, and user impact.

  • Prioritization – Use assigned severity levels to know which errors to tackle first.

  • Release tracking – Associate errors with specific app versions to understand regressions.

  • Breadcrumbs – Follow the sequence of user actions leading up to an error to diagnose it.

  • Integrations – Connect Sentry to collaboration platforms like Slack, Jira, and GitHub.

Sentry is quick to set up with most programming languages and frameworks. Pricing starts at $26/month.


Airbrake provides simple yet robust error monitoring across the frontend and backend. Its key features include:

  • Real-time error reporting – Get instant alerts for JS exceptions, failed network requests, and other mishaps.

  • Automated grouping – Airbrake aggregates similar errors into issues to streamline work.

  • Deployment tracking – Associate problems with new code deployments to pinpoint regressions.

  • Contextual debugging – Inspect comprehensive event details like environment variables, request parameters, session data, and stack traces.

  • Integrations – Connect with collaboration tools like Slack, GitHub, and more.

Airbrake offers a forever-free tier for small workloads and paid plans starting at $19/month.


LogRocket differentiates itself by recording videos of actual user sessions where errors occurred. This enables:

  • Session replay – Watch exactly what the user saw and did leading up to an error, step-by-step. Extremely helpful for diagnosing issues.

  • Network logs – Inspect detailed network activity like API requests, responses, headers, payloads, and timing.

  • Console logging – View the console output for session replays to aid debugging.

  • Error monitoring – Get alerts for unhandled exceptions, debugger statements, rejected promises and more.

  • Custom data – Log and analyze additional app-specific data.

  • Vital integrations – Connect tools like Redux, React Router, and React Native Error Handler.

LogRocket pricing starts at $29/month for 5,000 sessions.


Raygun has robust error and crash reporting capabilities specifically built for web and mobile apps. Features include:

  • Real-time alerts – Receive instant notifications when new frontend errors strike your users.

  • Full diagnostics – Raygun‘s error reports contain complete information like stack traces, request parameters, app environment details, and custom user data to accelerate debugging.

  • Error grouping – Similar errors are aggregated into issues to help you focus on the most widespread problems first.

  • Crash reporting – Detect and analyze fatal JavaScript crashes.

  • Custom dashboards – Visualize errors, customer impact, and app health with fully customizable dashboards.

  • Integrations – Connect with collaboration platforms like Slack, GitHub, Datadog and more.

Raygun offers a free trial. Paid plans start at $19/month.

Firebase Crashlytics

Firebase Crashlytics makes frontend monitoring incredibly easy by auto-detecting crashes and other fatal issues. Features include:

  • Lightweight – Requires minimal implementation while providing robust error detection.

  • Automatic crash reporting – Catches fatal JS errors and anomalies without any configuration.

  • Insights – Crashlytics analyzes trends to highlight spikes and regressions that require attention.

  • Alerting – Get real-time notifications when new problems arise or old ones reoccur.

  • Prioritization – Crashlytics ranks issues by impact, highlighting the most severe customer-facing problems.

  • Stability metrics – Track overall app health metrics like crash-free user rates.

  • Popular app integrations – Works seamlessly with solutions like React Native.

Crashlytics has a free tier and paid plans through Firebase.


AppSignal consolidates multiple monitoring capabilities into one well-designed platform. Key features include:

  • Error tracking – Detect and group errors with complete diagnostics.

  • Performance metrics – Measure page load speeds, request throughput, and other vitals.

  • Anomaly detection – Get alerted on unusual metric spikes.

  • Deployment tracking – Associate deployments with errors and monitoring changes.

  • Server monitoring – Track utilization, queue sizes, and health metrics.

  • Custom dashboards – Build detailed monitoring dashboards tailored to your stack.

  • Popular frameworks – Out-of-the-box support for Ruby, Elixir, and Javascript.

AppSignal starts at $49/month for up to 5,000,000 monthly events.

New Relic

New Relic is an industry leader in performance monitoring. For frontend monitoring, it provides:

  • Error tracking – Detect and group JS errors with complete stack traces and context.

  • Performance monitoring – Measure page load times, throughput, requests, and more.

  • Browser monitoring – Understand frontend performance across different browsers.

  • Segment analysis – Slice and dice performance metrics by categories like device type, region, and browser version.

  • Alerting – Get notified for error rate spikes, slow endpoints, and other issues.

  • Custom dashboards – Build visual dashboards to track the frontend KPIs important to you.

  • Popular integrations – Plug into React, Angular, and other frameworks.

New Relic offers a Lite tier with basic features free forever, along with paid plans.

Key Considerations for Picking a Tool

With so many great options available, choosing a frontend monitoring tool ultimately depends on your tech stack, team size, and budget.

Here are some key criteria to guide your decision:

  • Alerting – Real-time notifications for new errors and anomalies are critical. All tools above support this well.

  • Contextual data – Look for detailed diagnostics like stack traces and source maps to accelerate debugging.

  • User session tracking – Replaying failing user sessions is invaluable for diagnosing issues. LogRocket specializes here.

  • Customizability – Prioritize tools that allow custom dashboards, metrics, and alerts tailored to your app. Raygun and New Relic are very configurable.

  • Integrations – Consider which collaborations tools like Slack, Jira, and GitHub each solution supports out-of-the-box.

  • Framework support – Factor in which JavaScript frameworks and libraries each tool officially integrates with.

  • Pricing – Weigh pricing models based on your scale, workload, and budget. Firebase Crashlytics and Airbrake have very generous free tiers for example.

Doing thorough evaluations upfront ensures you choose the right frontend monitoring platform aligned with your needs, workflows, and budget.

Implement Robust Frontend Monitoring Today

If you made it this far – congratulations! You now understand why frontend monitoring is critical for delivering flawless user experiences.

You‘re also equipped with a comprehensive overview of the top tools available to monitor for damaging errors, performance issues, crashes, anomalies, and more before customers notice them.

My advice is to start implementing frontend monitoring right away. Don‘t wait for your users to complain about bugs – proactively detect problems so you can fix them immediately.

Within minutes, you can set up Sentry, Raygun, LogRocket, or any of these excellent solutions. Once in place, you‘ll gain invaluable visibility into your frontend‘s health and start improving it.

Here‘s to building stellar web and mobile applications that your users love. Happy monitoring!

Written by