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Web Vitals

Silktide loads each page in a real browser and summarizes how fast it feels to use, as a set of standard speed measurements and an overall score. This is a summary of the page's performance rather than a specific problem to fix.

The measurements are the industry-standard ones popularized by Google's , each graded against its public threshold:

  • First Contentful Paint - when something first appears on screen. Under 1.8 seconds is good; over 3 seconds is poor.
  • Speed Index - how quickly the visible page fills in. Under 3.4 seconds is good; over 5.8 seconds is poor.
  • Time to Interactive - when the page reliably responds to input. Under 3.8 seconds is good; over 7.3 seconds is poor.
  • Total Blocking Time - how long scripts block the page from responding while it loads. Under 200 milliseconds is good; over 600 milliseconds is poor.
  • First Input Delay - the longest a visitor's first interaction could be delayed. Under 130 milliseconds is good; over 250 milliseconds is poor.

Largest Contentful Paint and Cumulative Layout Shift have their own checks - see Largest Contentful Paint and Layout shifts.

Why this matters

These measurements describe speed the way visitors experience it - when the page appears, when it fills in, when it responds - rather than raw technical figures like file sizes. Slow vitals cost real outcomes: visitors abandon pages that take too long, and Google uses Core Web Vitals as a search ranking signal.

As a summary, this is where to start when a page feels slow: it shows which aspect of loading is the problem, and the individual speed checks then point to the specific causes and fixes.

How Silktide tests this

  1. Load the page in a real browser, using the device type, connection speed, and test location configured for your speed tests.
  2. Record the timing measurements above during the load, and grade each against its public threshold.
  3. Combine them into the page's overall performance score, from 0 to 100.

Troubleshooting

My numbers differ from other tools

These are controlled lab measurements: one load, on the device, connection speed, and location configured for your speed tests. Tools built on real visitor data (such as field Core Web Vitals reports) aggregate many different devices and networks, so the two can legitimately differ without either being wrong.

The results vary between scans

Some variation is normal - servers, networks, and third-party scripts all fluctuate. Watch the trend over time rather than a single reading, and treat consistent poor grades as the signal to act on.

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Web Vitals | Silktide Help