Page speed
How fast a page loads and becomes usable. It affects rankings modestly and conversion rate substantially.
In depth
What it really means
Page speed covers everything from server response through to the moment a user can actually interact. Core Web Vitals are the specific metrics Google uses for ranking, but speed matters well beyond them.
The honest framing is that speed is a conversion problem that happens to have a small ranking benefit. Selling it internally on ranking undersells it, because the revenue case is far stronger.
How it works
- The browser requests the page and waits for the server, measured as TTFB.
- HTML arrives and rendering begins.
- Images, fonts, CSS and JavaScript load and block rendering to varying degrees.
- The page becomes visually complete and then interactive.
Pros & cons
Pros
- Direct, measurable effect on conversion rate.
- Contributes to ranking through page experience.
- Improves crawl efficiency, since faster pages get crawled more.
Cons
- Fixes are engineering work with real cost.
- Third-party scripts are often the problem and often untouchable politically.
- Diminishing returns past a point.
Common mistakes
- Optimizing lab scores instead of real-user field data.
- Ignoring third-party tags, which are usually the largest single cause.
- Serving oversized images, still the most common and most fixable issue.
- Testing on office wifi rather than on the connections your users actually have.
Best practices
- Compress and correctly size images, and serve modern formats.
- Audit third-party scripts and remove the ones nobody uses.
- Defer non-critical JavaScript and inline critical CSS.
- Measure with field data from Search Console, not Lighthouse alone.
- Build the business case on conversion rate, which is where the return is.
FAQs
Does page speed affect rankings?
Modestly, through Core Web Vitals and page experience. The conversion rate effect is considerably larger and is the better reason to invest.
What is a good page load time?
Under 2.5 seconds for Largest Contentful Paint at the 75th percentile of real users. Faster is better but returns diminish.
What slows pages down most?
Unoptimized images and third-party scripts, in that order. Both are usually fixable without a rebuild.
Lighthouse or Search Console?
Search Console for assessment, since it uses real user data. Lighthouse for diagnosis, since it tells you what to fix.
Keep reading
Related on LymLyt
Beyond LymLyt
Further reading
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