Web Performance Learning Hub
All about site speed: PageSpeed checker, Core Web Vitals (LCP, INP, CLS) glossary, how-to guides (Web Vitals measurement, performance debugging), research (CDN latency).
Glossary (5) all →
Service Worker — Offline-First and PWA
Service Worker — a JS thread between browser and network. Offline cache, push notifications, background sync. PWA foundation.
p99 Latency — What It Is and Why
p99 latency — the 99th percentile of response time. Why it matters more than median, how to measure, target values.
React Server Components (RSC) 2026
React Server Components — components running on the server. Next.js App Router, streaming, zero JS in client bundle.
Server Actions (Next.js) — 2026
Server Actions — async functions on the server called from React components. No API routes. Progressive enhancement.
Core Web Vitals — LCP, INP, CLS in 2026
Core Web Vitals are Google's three key UX and ranking metrics: LCP, INP (replaced FID), CLS. Thresholds, how to improve.
How-to (5) all →
How to Measure Web Vitals in Production
Core Web Vitals: LCP, INP, CLS. Field data via web-vitals lib, RUM, Google Search Console. Alert on regressions.
How to Enable Brotli Compression in nginx 2026
Brotli (Google) — compression 15-25% more efficient than gzip. Install ngx_brotli module, configure, verify.
How to Optimize LCP (Largest Contentful Paint) 2026
Step-by-step LCP optimisation: priority hints, preload hero image, defer JS, critical CSS. Core Web Vitals threshold ≤ 2.5s.
How to Reduce Website TTFB [2026]
Step-by-step TTFB reduction: CDN, caching, DB optimization, HTTP/2. Online measurement.
How to Check Website Speed Online [2026]
Website speed check: LCP, CLS, INP, FCP, TTFB. Free tools, monitoring, optimization.
Alternatives (2) all →
GTmetrix Alternatives 2026 — Site Speed Analysis
GTmetrix free tier shows only one tab of data. Alternatives: Enterno.io Speed, PageSpeed Insights, WebPageTest, Pingdom.
WebPageTest Alternatives 2026 — Catchpoint, Enterno
WebPageTest by Catchpoint is an open deep performance analyzer. Lighter-UX alternatives: Enterno.io, GTmetrix, PageSpeed Insights.