SEO Engine Performance & Tuning 2 — Questions and Answers
Question 1: Which Core Web Vital measures the time from when a user first interacts with a page to when the browser responds to that interaction?
- First Contentful Paint (FCP)
- Interaction to Next Paint (INP) (Correct answer)
- Largest Contentful Paint (LCP)
- Cumulative Layout Shift (CLS)
Correct answer: Interaction to Next Paint (INP)
INP replaced FID as a Core Web Vital in 2024, measuring responsiveness from interaction to the next visual update.
Question 2: A website scores 0.35 on Cumulative Layout Shift. How does Google classify this score?
- Good
- Needs Improvement
- Poor (Correct answer)
- Critical
Correct answer: Poor
CLS scores above 0.25 are classified as Poor; Good is below 0.1 and Needs Improvement is 0.1–0.25.
Question 3: Which HTTP header instructs the browser to cache a resource for a specific duration without revalidating?
- ETag
- Last-Modified
- Cache-Control: max-age (Correct answer)
- Expires
Correct answer: Cache-Control: max-age
Cache-Control: max-age directs the browser to cache a resource for the specified number of seconds without server revalidation.
Question 4: What is the primary SEO benefit of implementing HTTP/2 on a web server?
- Enables JavaScript lazy loading
- Allows multiplexing multiple requests over a single connection (Correct answer)
- Compresses HTML automatically
- Forces HTTPS on all pages
Correct answer: Allows multiplexing multiple requests over a single connection
HTTP/2 multiplexing allows multiple requests and responses to travel over one TCP connection simultaneously, reducing latency.
Question 5: Which image format typically provides the best compression for photographic web images while maintaining SEO-friendly file sizes in modern browsers?
- PNG
- GIF
- WebP (Correct answer)
- BMP
Correct answer: WebP
WebP provides 25–35% better compression than JPEG/PNG for photographs while supporting both lossy and lossless modes.
Question 6: A site's Time to First Byte (TTFB) is consistently above 800ms. Which action MOST directly addresses this issue?
- Minifying CSS files
- Implementing server-side caching or a CDN (Correct answer)
- Reducing image dimensions
- Adding a sitemap.xml
Correct answer: Implementing server-side caching or a CDN
High TTFB is a server response issue; server-side caching and CDNs reduce backend processing and physical distance to the user.
Question 7: When using lazy loading for below-the-fold images, which HTML attribute should be used?
- loading="defer"
- loading="lazy" (Correct answer)
- loading="async"
- loading="background"
Correct answer: loading="lazy"
The native HTML loading="lazy" attribute tells the browser to defer loading images until they approach the viewport.
SEO Engine Performance & Tuning 2
Which Core Web Vital measures the time from when a user first interacts with a page to when the browser responds to that interaction?