Find, triage and recreate bugs 100% automatically

Be alerted to bugs immediately
Receive Slack notifications about problems immediately upon new release. Kuoll smartly merges JavaScript errors by stack traces.

Triage bugs in minutes
Kuoll dashboard shows how many users are affected by specific bugs. Understand the impact of each bug within minutes of new release.

Replayable debug-friendly user sessions
Each Slack bug notification includes a link to a replayable user session. The session shows the record of
1) how user interacted with the web page, and
2) how the code was running on the end user machine.

This is the same information that is available in the web browser developer’s tools. Kuoll is like a time machine which allows the developer to see and investigate what went wrong on the user machine at the moment when a problem occured.

Install and use
Web app monitoring and customer support automation is easy with Kuoll. You may also try our online demo without registration. It provides full overview of Kuoll features.

Create account
Create account to get your Kuoll APIKEY.

Copy-paste code snippet
Copy code from the API introduction page. We have async, sync and npm-based version.

Feel free to contact us if you have a question.

Run the web app
Run your new build in local development, staging and production environment.

Add bot to Slack
Bugbot by Kuoll sends a notification each time it finds unfamiliar JavaScript error or unfamiliar erroneous server reply. Each notification has link to the replayable debuggable user session.

See user sessions
Replay user session and learn how the user event caused network request, HTML DOM changes, and JavaScript system API calls.

Core technology
Kuoll JavaScript code records debuggable user sessions and monitors a web application. When Kuoll code detects JavaScript Errors or a server XHR error replies, it uploads debug-friendly user session to Kuoll server.

Kuoll sends a Slack notification whenever it identifies a novel issue. The dashboard displays instance count of unique errors and the number of users affected by each.

Each user session contains

user events,
replayable DOM-mutations,
network requests (with a complete headers and content),
JavaScript execution flow, including calls and callbacks of Promise, setTimeout, setInterval methods.
All events are connected to cause-effect chains, eliminating the need for the developer to reproduce bugs. Cause-effect chains provide all information necessary to analyze bugs directly in the record and to address them extremely efficiently.

The highly optimized library of client-side JavaScript code is at the core of Kuoll’s industry-best recording script.