Understanding Metrics

How to interpret each metric.

Mark Zeman avatar Steve Souders avatar Tammy Everts avatar +2
17 articles in this collection
Written by Mark Zeman, Steve Souders, Tammy Everts and 2 others

Why are my LUX metrics different from those reported by CrUX?

Understanding why your LUX numbers may not match up with the Chrome User Experience Report (CrUX) and what to do about it.
Cliff Crocker avatar
Written by Cliff Crocker
Updated over a week ago

When should I use average, median, and other percentiles?

How to choose between average, median, 75th percentile, and 95th percentile
Joseph Wynn avatar
Written by Joseph Wynn
Updated over a week ago

What do the different SpeedCurve metrics represent?

Glossary of metrics you can track with Synthetic and LUX Real User Monitoring.
Steve Souders avatar
Written by Steve Souders
Updated over a week ago

Why are my Lighthouse scores different from my other test results?

Here's why your Lighthouse scores in SpeedCurve might be different from the scores you get elsewhere.
Tammy Everts avatar
Written by Tammy Everts
Updated over a week ago

Why are my Synthetic and LUX numbers different?

It's quite typical for RUM metrics to be faster than Synthetic. Here's why that is – and why you still need both types of monitoring.
Tammy Everts avatar
Written by Tammy Everts
Updated over a week ago

Why are the SpeedCurve results different from my other test results?

Here's why. But remember: the most important thing to track is consistency and changes within a single testing tool and settings.
Mark Zeman avatar
Written by Mark Zeman
Updated over a week ago

Why does my fully loaded time fluctuate so much?

Some pages may have very high or fluctuating fully loaded times. Here's why.
Joseph Wynn avatar
Written by Joseph Wynn
Updated over a week ago

Lighthouse scores and audits

How to find and track your Lighthouse scores and audits.
Tammy Everts avatar
Written by Tammy Everts
Updated over a week ago

How to remove a single data point from your test averages

If outlier test results are bumping out your averages, here's how to exclude them.
Tammy Everts avatar
Written by Tammy Everts
Updated over a week ago

Hero rendering times

How we identify the hero rendering metrics, plus how to add element timing.
Mark Zeman avatar
Written by Mark Zeman
Updated over a week ago

How is Speed Index calculated?

What is the Speed Index score and why does it sometimes not align with your other metrics?
Tammy Everts avatar
Written by Tammy Everts
Updated over a week ago

Blocking JS & CSS

How SpeedCurve detects blocking JavaScript and stylesheets
Steve Souders avatar
Written by Steve Souders
Updated over a week ago

Why don't my charts change when I select median, average, and 75th/95th percentile?

Joseph Wynn avatar
Written by Joseph Wynn
Updated over a week ago

LUX Query Timeouts

How to avoid having LUX queries time out.
Steve Souders avatar
Written by Steve Souders
Updated over a week ago

Data Protection & GDPR Compliance at SpeedCurve

Mark Zeman avatar
Written by Mark Zeman
Updated over a week ago

Google PageSpeed Insights

Now deprecated in favour of Lighthouse Performance
Mark Zeman avatar
Written by Mark Zeman
Updated over a week ago

Time Labels in Charts

What exactly do the time labels in the charts mean?
Steve Souders avatar
Written by Steve Souders
Updated over a week ago