This feature is quite an interesting technical feat, considering that it shouldn't really be possible to get error information form 3rd party scripts. See [this](https://github.com/loggly/loggly-jslogger/issues/22) and [this](https://github.com/logentries/le_js/issues/51) for discussions.
Ranked in these QuestionsQuestion Ranking
Pro Generous free plan
Free plan allows for up to 5000 events/month, customizable rate limits, integrations (e.g. with Slack), multiple users, and 30 day retention.
Pro Integrates with Slack
Rollbar can be integrated with Slack to send notifications of various event to a set Slack channel based on customizable rules.
Pro Stack traces (traceback)
Stack trace with function calls and line numbers.
Pro Client library is open source
Pro Custom error grouping
Pro Capture any uncaught errors
Rollbar allows sending any log messages to Rollbar not just exceptions enabling you to go back and check for missed exceptions.
Pro Supports "deploy" events
You can easily send "deploy" events with
curl, so that you know to which version the errors apply. Errors are grouped automatically by name/type, but if the re-occur after a deploy, they'll be shown again above the deploy in the timeline.
Pro Multiple integration options
Asana - Create and resolve Asana tasks
Bitbucket Issues - Create and manage Bitbucket Issues
Campfire - Get alerts in your Campfire room
Flowdock - Get messages in your flow
GitHub Issues - Create and manage GitHub Issues
HipChat - Get alerts in your HipChat room
JIRA - Create, resolve, and reopen JIRA issues
PagerDuty - Trigger and resolve incidents in PagerDuty
Pivotal Tracker - Create and manage Pivotal Tracker stories
Slack - get alerts in a chatroom or group
Sprintly - Create and manage Sprintly items
Trello - Create and manage cards in Trello
VictorOps - Trigger and recover alerts in VictorOps
Webhook - Post JSON payloads to arbitrary URLs
Email - get notifications and daily summaries
Pro Source maps support
Source map support is used to reference original source code in cases where the code is minified.
Pro Error filtering
Rollbar allows ignoring specific exceptions simply by adding the error message to the ignoredMessages array.
It's very easy to integrate and tracks every user events, you get real-time updates. A must-have tool on your site to track down bugs and make the user experience better.
Pro AJAX errors
Helps you know when the API call is failing so that you can quicky get to it.
Pro Event telemetry to reproduce error
Records action that led to the error which makes it easy to reproduce the error faster. Events recorded are console logs, network calls, route changes and user events, like clicks and inputs.
Pro Network performance monitoring
AJAX monitoring shows which calls are running slow and how many calls the app is making to the backend. Also, provides data transfer reports and throughput reports.
Allows integrating various notification channels like Slack, Hipchat & Email. Notifies whenever there's a new error or a resolved error appears again.
Pro Page load performance monitoring
Monitors page load performance along with the breakdown like Query stalling, SSL, TCP Handshake etc. It also provides in-depth monitoring, including duration filtering, URL filtering and AJAX calls made from the page.
Pro Drag & drop source map support
It's really easy to debug minify code. Source map support, not just beautifies the code, but also fetches code context.
Pro Daily error reports
Daily reports help understand anomalies that triggers errors. Also, gives top erroneous browsers, URLs etc within the report.
Pro There's a free plan
ErrLytics provides a free plan which helps to monitor small-scale websites, a feature that is mostly absent in other services.
Con No context for some errors
Con Old-school UI
Built with the default Bootstrap theme. Looks like 2011.