Know when your web app breaks breaks

Log errors right from the browser

Track errors when they happen. You are notified when something goes wrong.

See click trails, screenshots and application state

Fixing bugs gets a lot easier when you know how they happened

Sleep well

Be safe knowing that no hidden bugs are silently ruining your users' experience

Free to try
Works out of the box with any framework
React, Angular, Vue.js, JQuery, Aurelia and Backbone.js are all supported out the box

JavaScript error logging for developers

Create a flawless user experience. Capture any error caught on your site, and see it immediately in the error log. You are notified when a new error occurs.

Unlock development super powers

Playback the clicks that lead to the error, with a screenshot straight from the users' device.
Avoid guesswork, and see exactly how the error happened.

Dead simple integration

Just add the following script tag, set up an account, and your JavaScript error tracking is ready.

<script src="//"></script>

The CatchJS script will set up JavaScript error monitoring directly from your users' browsers. It will automatically collect uncaught exceptions and present a detailed log of their circumstances. Read more about setting up CatchJS.

Error tracking without the bloat

Create delightfully fast websites. Don't let error tracking slow things down. The CatchJS library is up to 8 times smaller than our competitors, only 1.77KB gzipped.

CatchJS vs competitors (lower is better)
The CatchJS error logging library is fast. It has an up to 8x smaller file size than our competitors.
The code view shows you exactly where in the code the error happened.

See exactly where the error happened

Get the full error context, and see exactly what went wrong. Source maps will be collected and applied automatically, with no action needed from you.

GDPR ready

We track JavaScript exceptions, not users. Services that perform user tracking will store personal data, and thus require collecting explicit consent from the user, according to EU law. CatchJS is privacy preserving by default, and does not require the extra work of collecting such consents.

GDPR ready

It's not just for errors

Track and log whatever data you'd like, using the catchjs.log() function. It is like the developer console, but logging remotely from your users' device. In addition to JavaScript error reporting, you get a dead simple way to monitor any event of interest.

What you need to keep things working

Email notifications

Get alerts when new errors happen, along with weekly summaries.


See the user's screen as the error happened

Click trails

See what clicks lead to the error state.

Stack traces

See the stack trace of the error, and track down its root cause


Pinpoint when the error started happening with the error rate graph

Browser stats

See at a glance in which browsers the trouble is happening


Find the exact circumstances behind each error with the details view

We're a lot cheaper than having a broken web app

There are no hidden costs and no surprises, just a flat monthly rate.


per month

  • Free 14 day trial
  • 1 000 logged errors per month
  • 1 000 log API calls per month
  • 1 domain per account
  • Email notifications
  • Screenshots
  • Click trails
  • Priority support
Start tracking errors


per month

  • Free 14 day trial
  • 100 000 logged errors per month
  • 100 000 log API calls per month
  • 1 domain per account
  • Email notifications
  • Screenshots
  • Click trails
  • Priority support
Start tracking errors


per month

  • Free 14 day trial
  • 1 000 000 logged errors per month
  • 1 000 000 log API calls per month
  • 25 domains per account
  • Email notifications
  • Screenshots
  • Click trails
  • Priority support
Start tracking errors
Are you part of an open source software project? We have much gratitude to the open source software community, and therefore provide a free subscription to such projects. Click here to apply.