speedlify2

Lighthouse lab metrics, Axe, and Chrome UX Report field data for a list of sites recorded and compared over time.

Charts Measurement runs Embed a score

Charts

Pulls the most recent measurement of every site (excluding starter projects). Tooltips are only shown on green (well scoring) data points.

Page Weight vs LCP 15 sites

2.5 s 4 s 1 kB 10 kB 100 kB 1 MB 10 MB 10 s Page Weight Largest Contentful Paint
2 within 2.5 s 2 to 4 s 11 over 4 s

JavaScript Weight vs LCP 15 sites

2.5 s 4 s 0 1 MB 10 s JavaScript Weight Largest Contentful Paint
2 within 2.5 s 2 to 4 s 11 over 4 s

TTFB vs LCP 15 sites

2.5 s 4 s 1 s 10 s Time to First Byte Largest Contentful Paint
2 within 2.5 s 2 to 4 s 11 over 4 s

Web Font Weight vs CLS 15 sites

14 within 0.1 0 to 0.25 1 over 0.25

Third Party vs Performance 15 sites

Usually things like analytics, embeds, fonts, tag managers, ads weighted against Lighthouse’s Performance score.

90 50 0 1 MB 0 25 50 75 100 Third-Party Weight Performance Score
2 scoring 90 and above 12 scoring 50 to 90 1 scoring under 50

DOM Elements vs Performance 15 sites

DOM element count against Lighthouse’s Performance score. A big document is paid for in style and layout work on every frame.

90 50 10 100 1,000 0 25 50 75 100 DOM Elements Performance Score
2 scoring 90 and above 12 scoring 50 to 90 1 scoring under 50

JavaScript Weight by Site Generator 10 sites

One row per generator, one dot per site, ordered by median.

Across 1 generators with at least five sites each: twenty more were detected too rarely in this data set.

1 MB JavaScript Weight WP Rocket 10 757 kB
Scroll sideways for the rest of the scale.

Client Rendering by Generator 14 sites

Sites that painted nothing with scripts disabled, by the tool their page reports building it. One row per generator: a dot for how many of its sites were judged, a dot for how many came up blank, and a line joining them — so the length of the row is the size of the sample the finding came out of.

2 empty pre-JavaScript blank pages from 14 measured sites.

0 2 4 6 8 10 Sites WP Rocket No generator tag 1 of 10 1 of 2
Sites judged Drew nothing without JavaScript Scroll sideways for the rest of the scale.

The other 2 generators flagged nothing across 2 judged sites between them — mostly on samples of a handful of sites each.

TTFB by Host 10 sites

1 s Time to First Byte Cloudflare 5 Self-hosted 5 628 ms 634 ms
Scroll sideways for the rest of the scale.

Lab vs Field LCP 11 sites

One row per site: a dot for what our throttled lab run measured, a dot for what real users actually saw (Chrome’s field p75) and a line joining them.

The lab is slower than reality on 11 of these and faster on 0.

Lab Field, within 2.5 s Field, to 4 s Field, over 4 s