Uncaught exceptions
NorthDuty listens for pageerror events — uncaught JavaScript exceptions that break page functionality — and includes them in the check result.
JavaScript Error Monitoring
NorthDuty detects JavaScript errors and console.error messages on every health check using a real browser — so front-end script failures show up in your monitoring timeline, not in customer support tickets.
Catch the script errors that break buttons while the page still looks fine.
Front-end errors are invisible to basic uptime tools
A page can return HTTP 200 while a critical JavaScript error prevents the checkout button, login form, or product page from working. Ping-based uptime checkers don't catch this because they never run the page's JavaScript.
NorthDuty runs every health check in a real Chromium browser. It captures uncaught JavaScript exceptions and meaningful console.error messages, reports them in the health timeline, and uses them to calculate the errors component of the health score.
How NorthDuty monitors JavaScript errors
Every health check captures front-end script failures the same way a real user's browser would.
console.error messages
Meaningful console.error output is captured alongside page exceptions, so deeper front-end failures are visible without opening DevTools.
Health score impact
JavaScript errors count as critical failures in the errors component of the health score (20% weight). They directly affect the 0–100 score reported for each check.
Real browser, no agent
No JavaScript snippet required. NorthDuty uses a real Chromium browser on every check, so errors are caught exactly as a visitor's browser would experience them.
Why JavaScript error monitoring matters
Most website failures in production are front-end failures — not server outages.
- Catch broken checkout buttons, login forms, and JS-powered UI before customers hit them
- See front-end failures in the same timeline as uptime and SSL checks
- Get alerted when a deploy introduces script errors on important pages
- No code instrumentation or agent installation — runs from a real browser
- JavaScript errors count toward the health score, so silent failures lower the score
How it works
JavaScript error monitoring is automatic on every health check. No setup beyond adding a URL.
1
Add your URL to NorthDuty
Create a project and add your site URL. Health monitoring, including JavaScript error detection, starts automatically.
2
NorthDuty runs a real browser on every check
Each run launches a Chromium browser, navigates to the page, and captures any uncaught exceptions or console.error messages.
3
Errors appear in the health timeline
Failed script checks are included in the run result and reduce the errors component of the health score.
4
Set an alert threshold
Use a 'health score below' alert rule to get notified when JavaScript errors push the score below your acceptable threshold.
Related NorthDuty Pages
Explore pricing, feature details, solution pages, and related tools connected to this website monitoring use case.
Pricing
Pricing
NorthDuty pricing for website monitoring: Free, $29 Starter, $79 Pro, $199 Business, and $499 Enterprise plans.
Compare pricing plansHub
Features
Explore NorthDuty features: website health checks every 5 minutes, screenshot-based visual change detection, and AI-suggested user journey monitoring in one project.
Browse FeaturesHub
Solutions
Explore NorthDuty solutions for ecommerce website monitoring, SaaS website monitoring, agency website monitoring, and startup website monitoring.
Browse SolutionsFeature
Uptime Monitoring
Monitor uptime every 5 minutes by default with HTTP, SSL, DNS, blank-page detection, broken resources, JavaScript errors, and API call tracking.
Explore Uptime MonitoringFeature
API Monitoring
Run scheduled API monitors with chained requests, status, JSON, header, and latency assertions, plus alerts when an endpoint breaks.
Explore API MonitoringFeature
Website Performance Monitoring
Monitor website performance signals, response timing, and rendering context on the pages and journeys that affect revenue, leads, and trust.
Explore Website Performance MonitoringFeature
Website Monitoring
Learn how NorthDuty combines health checks, screenshot diffs, and editable user journeys in one website monitoring project.
Explore Website MonitoringFeature
Alerting
Send NorthDuty alerts to email, Slack, Teams, Discord, Google Chat, webhooks, Telegram, WhatsApp, and SMS.
Explore AlertingArticle
How to Monitor JavaScript Errors on a Website
Learn how to monitor JavaScript errors on important website pages so front-end failures do not break forms, checkout, signup, or page rendering.
Read How to Monitor JavaScript Errors on a WebsiteFrequently Asked Questions
Answers to common questions about this monitoring feature and when teams should use it.
Does NorthDuty catch JavaScript errors automatically?
Yes. Every health check runs a real browser that captures uncaught JavaScript exceptions and console.error messages. No setup beyond adding a URL.
How do JavaScript errors affect the health score?
JavaScript errors count as critical failures in the errors component of the health score (20% of the total). They directly reduce the 0–100 score.
Do I need to install a JavaScript snippet on my site?
No. NorthDuty checks your site externally from a real browser — there's nothing to install on the site itself.
What's the difference between NorthDuty and Sentry for JavaScript errors?
Sentry monitors errors from real user sessions using an installed SDK. NorthDuty monitors errors from scheduled synthetic checks using a real browser — a complementary approach that catches errors before users do, on the pages and routes you choose to monitor.
Call To Action
Start monitoring your website with NorthDuty today.
Monitor JavaScript errors on your most important pages with a real browser — no installation required.
Start on the free plan — add your base URL and monitoring starts in minutes.