GlitchTip's open source platform makes monitoring software easy. Track errors, monitor performance, check site uptime all in one place. Compatible with Sentry client SDK but easier to run and entirely open source.

Sentry’s real-time error tracking gives you insight into production deployments and information to reproduce and fix crashes—before your users contact you.

Enhance your frontend applications with real-time JavaScript error tracking that captures detailed analytics, filters out noise, and offers customizable rules. Integrate seamlessly with existing systems or use separately by leveraging extensive documentation and support from a committed team starting at $49.

App Enlight- provides a helpful interface to let you and your team save time spent on debugging and reproducing errors and performance problems from a production environment.

Airbrake collects errors generated by other applications, and aggregates the results for review.

May be the coolest cloud based error logger for .NET web applications. Based on the de-facto standard error component ELMAH, logging errors from your webserver requires nothing more than installing a NuGet package.

Reactflow give insight for marketers, product managers and UX designers about how their users experience their website. It reconstruct visitors activity like a movie for playback, while providing extracted console log, Heatmaps and funnel analytics.

Unbloated, yet feature rich. CatchJS provides JavaScript Error Tracking the way it should be. It notifies you when new errors happen, and gives you stack traces, screenshots, click trails, source maps so you can reproduce and fix the error easily.

Errbit is a tool for collecting and managing errors from other applications. It is Airbrake (formerly known as Hoptoad) API compliant, so if you are already using Airbrake, you can just point the airbrake gem to your Errbit server.

Monitor actual user JavaScript errors as they happen. JSMonitor features real-time alerts, prioritization, and tracking features to squash JavaScript errors forever.

A unified logger that routes logs to various logging libraries and cloud providers while providing a fluent API for specifying log messages, metadata and errors.