Microsoft's experimental Network Efficiency Guardrails feature in Edge automatically detects common resource-loading performance issues — oversized images (>200 KB), uncompressed text resources, and large data URLs (>100 KB) — using Document Policy and the Reporting API. Developers opt in via response headers, view violations in DevTools, and can collect structured reports from real users in production. The guide covers enabling the feature in Edge 146+, configuring headers in a Nuxt 4 app, and inspecting reports locally or via a backend endpoint.
Table of contents
What are Network Efficiency Guardrails? Why this matters How Network Efficiency Guardrails work What gets reported? Enabling Network Efficiency Guardrails Opting your website into Network Efficiency Guardrails Viewing reports in DevTools Collecting reports in production Summary Monitor web performance with DebugBear Monitor Page Speed & Core Web Vitals2.6K Impressions