speedlify2

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

Charts Compare Measurement runs Embed a score

moderncss.dev

https://moderncss.dev/

99 100 77 100 ✓AXE ✓CWV

Ranks Overall #471 Built Awesome #387

Data from Sep 5, 2026, 8:08 PM UTC old Measured once a week · 3 runs since Aug 21, 2026

Elsewhere: PageSpeed Insights · Calibre · Treo · CrUX Vis · Scoring Calculator · Wayback Machine

Stack

Eleventy Built with Eleventy
Netlify Hosted by Netlify

Lighthouse Scores

99
Performance
no change
100
Accessibility
no change
77
Best Practices
no change
100
SEO
no change

Metrics Lighthouse, mobile Chrome UX Report

Core Web Vitals: passing 2 of 3 assessed from real Chrome users.

Field figures are the p75 across real Chrome users over a 28-day trailing window (2026-08-07 → 2026-09-03), origin-level.

Metric Lab Lighthouse Field Chrome UX Report
Value Change / range Trend p75 Distribution
LCP CWV Largest Contentful Paint 1.97 s good ↑ +10 ms (+0.5%) 1.95 s – 1.97 s 1.47 s good 93.4% 4.9% 1.7%
INP CWV Interaction to Next Paint — field only, no lab run can measure it n/a — — —
CLS CWV Cumulative Layout Shift 0 good → no change 0 – 0 0 good 97% 1.7% 1.3%
TBT Total Blocking Time 0 ms good → no change 0 ms – 0 ms n/a —
FCP First Contentful Paint 1.64 s good ↑ +839 ms (+104.9%) significant 800 ms – 1.64 s 1.37 s good 86.1% 7.9% 6.1%
Speed Index 1.64 s good ↑ +839 ms (+104.9%) significant 800 ms – 1.64 s n/a —
TTFB Time to First Byte 619 ms good ↑ +10 ms (+1.6%) 604 ms – 619 ms 669 ms good 80.4% 16.1% 3.5%

LCP Subparts lab observed, unthrottled

The subparts attribute LCP to your server, resource discovery, download, or rendering. Note that the Lab LCP shown above is throttled.

element render delay 90 ms
time to first byte 21 ms

Lab LCP vs Field LCP Chrome UX Report

Lab 1.97 s
Field p75 1.47 s

The lab LCP is 1.34× the field p75 — real users likely have above-average hardware or network connectivity.

Page weight

Metric Value Change / range Trend
Page Weight 139 kB ↑ +424 B (+0.3%) 138 kB – 188 kB
Requests 14 → no change 13 – 14
Third-party Weight 27.3 kB ↑ +311 B (+1.2%) 27.0 kB – 76.5 kB
Third-party CPU 6 ms → no change 6 ms – 7 ms
Unused JS 0 B → no change 0 B – 0 B
Unused CSS 0 B → no change 0 B – 0 B

By resource type

  • font 52.3% 72.5 kB · 3 req
  • other 16.1% 22.3 kB · 4 req
  • image 12.1% 16.8 kB · 3 req
  • script 9% 12.5 kB · 2 req
  • document 6.6% 9.1 kB · 1 req
  • stylesheet 4% 5.5 kB · 1 req

Third parties 3 entities

27.3 kB transferred, 6 ms on the main thread.

Carbon Ads imagescript 24.3 kB · 4 ms CPU
Plausible 2.7 kB · 2 ms CPU
Google/Doubleclick Ads 340 B · 0 ms CPU

Page health

Metric Value Change / range Trend
Main Thread Work 236 ms ↓ -51 ms (-17.7%) significant 236 ms – 287 ms
Long Tasks 0 ↓ -1 (-100%) significant 0 – 1
DOM Elements 303 → no change 301 – 303
Axe Violations Violating nodes from a full Axe CLI run (more than Lighthouse reports) 0 → no change 0 – 0
A11y Failures 0 → no change 0 – 0
A11y Failing Nodes 0 → no change 0 – 0

Main thread work

other 86 ms
style layout 84 ms
script evaluation 34 ms
paint composite render 15 ms
parse HTML 11 ms
script parse compile 6 ms

Axe violations axe-core 4.13.0, full rule set

0 violating nodes across 0 rules, 475 passing. This is a standalone Axe CLI run and is stricter than the subset Lighthouse already includes.

Hygiene

HTTPS HSTS CSP Clickjacking protection Origin isolation Trusted Types bfcache h2

Measurement log

Field history 25 weeks

Weekly p75 from the CrUX History API, backfilled in a single request.

Week ending LCPINPCLSFCPTTFB
2026-09-05 1.42 s — 0 1.35 s 666 ms
2026-08-29 1.42 s — 0 1.35 s 674 ms
2026-08-22 1.37 s — 0 1.35 s 677 ms
2026-08-15 1.34 s — 0 1.34 s 724 ms
2026-08-08 1.28 s — 0 1.27 s 754 ms
2026-08-01 1.27 s — 0 1.27 s 852 ms
2026-07-25 1.47 s — 0 1.46 s 1.03 s
2026-07-18 1.65 s — 0 1.65 s 1.06 s
2026-07-11 1.50 s — 0 1.53 s 1.06 s
2026-07-04 1.71 s — 0 1.72 s 1.12 s
2026-06-27 1.65 s — 0 1.65 s 890 ms
2026-06-20 1.48 s — 0 1.46 s 906 ms

Runs

Every stored run for this URL, newest first.

When Scores PerfLCPCLSTBTWeight RunsSpreadBenchTook Archive
Sep 5, 2026, 8:08 PM UTC 99 1.97 s 0 0 ms 139 kB 3/3 ±5 3,049 +23% 24.2s Wayback
Aug 29, 2026, 7:47 PM UTC 99 1.96 s 0 0 ms 138 kB 3/3 ±4 2,267 -9% 24.6s Wayback
Aug 21, 2026, 5:31 AM UTC 99 1.95 s 0 0 ms 188 kB 3/3 ±6 2,475 0% 28.5s Wayback

Embed this score

Use this web component to show moderncss.dev's scores on any website, updated whenever this instance re-measures. Don’t forget to bundle the speedlify2-score.js component code into your site! 

<speedlify2-score speedlify-url="https://www.speedlify.dev/" url="https://moderncss.dev/"></speedlify2-score>