Page Speed
The measure of how quickly a web page loads and becomes interactive for users. Page speed encompasses multiple metrics including server response time, resource loading, rendering, and interactivity, and directly impacts both search rankings and user experience.
Page speed is a multifaceted performance characteristic that Google has explicitly confirmed as a ranking factor. It is measured through multiple metrics including TTFB, FCP, LCP, and INP. Faster pages rank better, convert more, and retain users longer. Studies consistently show that each additional second of load time increases bounce rates by 20 to 30 percent.
For engineering teams, page speed optimization should be a continuous practice rather than a one-time effort. Audit performance with Lighthouse, WebPageTest, and Chrome UX Report data. Prioritize optimizations by impact: server-side improvements (caching, CDN, edge rendering) typically yield the largest gains, followed by reducing JavaScript payload, optimizing images, and eliminating render-blocking resources. For Next.js applications, leverage static generation, incremental static regeneration, and the Image component for built-in optimization. Set performance budgets that trigger alerts when page weight or load time exceeds thresholds. Monitor real user metrics alongside lab tests, as synthetic benchmarks do not capture the full range of devices and network conditions your users experience.
Related Terms
Core Web Vitals
A set of three Google-defined metrics that measure real-world user experience for loading performance, interactivity, and visual stability. Core Web Vitals are a confirmed ranking factor in Google Search.
Largest Contentful Paint (LCP)
A Core Web Vital that measures the time from page load start until the largest visible content element (image, video, or text block) is rendered on screen. Good LCP is 2.5 seconds or less.
Interaction to Next Paint (INP)
A Core Web Vital that measures the latency of all user interactions (clicks, taps, keyboard input) throughout the page lifecycle, reporting the worst interaction. Good INP is 200 milliseconds or less.
Cumulative Layout Shift (CLS)
A Core Web Vital that measures the total amount of unexpected layout shifts that occur during a page's entire lifespan. Good CLS is 0.1 or less, where layout shifts are calculated from the impact and distance of moving elements.
Time to First Byte (TTFB)
The duration from the user's request to the first byte of the server response reaching the browser. TTFB measures server-side processing speed and network latency, directly impacting all subsequent loading metrics.
Crawl Budget
The number of pages a search engine bot will crawl on your site within a given timeframe, determined by crawl rate limit and crawl demand. Crawl budget optimization ensures important pages are discovered and indexed efficiently.