Observe the errors that slip through
Even the most rigorous testing can't predict every browser quirk. Gain visibility into the silent frontend exceptions you might not know about.
docker run --rm -p 48043:8080 vantmetry/demo The blind spot
See exactly what broke. Fix it before it costs you a customer.
Caught before the crash vanished without a trace.
Start catching errors today
No infrastructure to manage. Predictable pricing with automatic log rotation that keeps storage costs from creeping up.
Start your trialAdd Vantmetry error tracking to this project. Install the CLI: npm install -g vantmetry-cli Then check docs: https://vantmetry.com/docs or run: vant register or vant trial
Core Capabilities
Automated Exception Capture
WebTransport and HTTP/3 powered near-instant telemetry for production visibility without head-of-line blocking. Falls back to sendBeacon on unsupported browsers. Learn how the ingestor processes events at scale.
Privacy-First Telemetry
Client-side redaction of emails and auth tokens before data ever leaves the browser. See our privacy notice for details.
Real-time Monitoring
Built-in monitoring and spike detection thresholds with webhook-based alerting.
Ready to dive in?
Explore our guides on tracker integration, automatic source map resolution, and analytical querying.
Read DocumentationFrequently Asked Questions
What is frontend observability?
Frontend observability is the ability to understand and monitor what happens in the browser. It captures JavaScript errors, exceptions, and performance metrics that traditional backend monitoring cannot see. Vantmetry lets you see every error that real users encounter.
How is Vantmetry different from Sentry or LogRocket?
Vantmetry is a lightweight, focused error tracker built for frontend observability. Sentry is a broader observability platform covering backend, mobile, and performance monitoring. LogRocket adds session replay and heatmaps on top of error tracking. Vantmetry keeps things simple with one flat-price plan and automatic log rotation that keeps storage costs from creeping up.
How does the tracker avoid blocking the main thread?
The Vantmetry tracker uses WebTransport (QUIC/HTTP3) for unidirectional event streams that do not block JavaScript execution. On browsers without WebTransport support, it falls back to sendBeacon and fetch with keepalive, both of which are non-blocking network primitives. Learn more in the tracker documentation.
What PII does Vantmetry mask, and how?
Client-side redaction masks email addresses, phone numbers, and common auth token patterns before data ever leaves the browser. PII detection runs on every error message and stack trace, so you capture the error without exposing sensitive user data.
How much does Vantmetry cost?
Vantmetry has one plan: Vantmetry Pro, at $29 / €29 per month. A 14-day free trial is included, no credit card required. The first 50 customers get a founding-customer price of $14.50 / €14.50 per month, applied automatically at checkout, for the life of their subscription.
What happens when my trial ends?
Dashboard access pauses when the 14-day trial ends. Your data is kept for 60 days after the trial ends, so upgrading resumes exactly where you left off. If you do not upgrade within that window, the project data is deleted.
How long is my data retained?
Paying customers have no time-based retention. Data stays as long as the subscription is active. When a project reaches its storage cap, the oldest events rotate out first so your newest errors always fit and your bill never grows.