Dash0 Raises $110M Series B at $1B Valuation

Last updated: May 13, 2026

Common Website Monitoring Issues

Troubleshoot web vital measurements, HTTP request trace linking, and CSP configuration.

This guide addresses common questions and troubleshooting scenarios when using the Dash0 Web SDK. It covers why web vitals may not appear for every page view, how to diagnose missing trace links between frontend requests and backend services, and how to configure Content-Security-Policy headers to allow telemetry ingestion.

Why are web vitals only measured for some page views?

Multiple factors limit web vital metric reporting frequency. Not every page view will have measurements for all web vital types. Sessions with high ratios of page transitions to page loads are particularly affected.

Limiting factors:

  • Web vital instrumentation only reports metric value changes
  • LCP measurements are reported only when the largest contentful element changes
  • INP measurements require user interaction
  • INP and CLS measurements are not performed when users have backgrounded pages

Why are my HTTP requests not linked to traces?

When HTTP request web events are not linked to expected traces, follow these troubleshooting steps:

  • Verify if the trace has been recorded
    • Check in Tracing if traces with dash0.trace.origin.type=WEB exist
    • If yes:
      • Review sampling strategy; Telemetry could have been dropped through the pipeline.
      • Not all request events have a corresponding trace
    • If no:
      • Make sure the target service is instrumented or continue reading
  • For cross-origin requests, verify the trace propagation is correctly configured. By default the Dash0 SDK only transmits trace context information for requests targeting the same origin your website is being served from. If the request in question is a cross-origin request you will need to specifically configure the SDK to allow trace context propagation to this origin. See the Dash0 SDK documentation for details on how to configure this correctly.
  • Verify the context propagators are configured correctly for the target service. The Dash0 SDK currently supports W3C Trace Context and AWS X-Ray as the trace propagation mechanisms. The target service needs to support one of them to link spans. See the Dash0 SDK documentation for details on how to configure this correctly.

I'm seeing Content-Security-Policy errors. What do I need to configure?

Websites with strict Content-Security-Policy directives must allow the ingest endpoint selected during SDK initialization via the connect-src directive.

Example:

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connect-src 'self' ingress.eu-west-1.aws.dash0.com ingress.us-west-2.aws.aws.dash0.com ingress.europe-west4.gcp.dash0.com

Further Reading

  • Set Up the Web SDK. Installation and configuration instructions for the Dash0 Web SDK, including endpoint URLs and authentication token setup.
  • Understand Web Vitals. Explains why web vitals may not be measured for every page view and how the metrics are calculated.
  • Correlate Sessions with Backend Traces. Shows how to drill down from frontend HTTP requests into full backend traces to debug performance issues.
  • Track HTTP Requests. Covers how HTTP requests are traced and linked to backend services, including cross-origin configuration requirements.
  • Proxy the Ingestion Endpoint. Describes how to route telemetry through your own infrastructure, including CORS configuration and authentication handling.