speedlify2

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

Measurement runs · Embed a score · Field data from the Chrome UX Report ·

covidtracking.com

https://covidtracking.com/

76 92 96 100 ✓CWV 7AXE

Data from Aug 20, 2026, 7:09 PM UTC — 24h old.

11ty Emeritus · 1 measurement · since Aug 20, 2026 · last attempt 24h

Stack

Detected on the same page load as the accessibility pass — the generator from <meta name="generator"> or the shape of the page, the host from response headers.

Gatsby 2.25.3 Built with Gatsby 2.25.3
GitHub Pages Hosted by GitHub Pages

Core Web Vitals field data, origin-level

Real Chrome users, 28-day window (2026-07-22 → 2026-08-18). This is what Google measures you on.

LCP 951 ms good
INP — no data
CLS 0 good

Scores

76
Performance
no change
92
Accessibility
no change
96
Best Practices
no change
100
SEO
no change

Lab metrics Lighthouse, mobile

Metric Current Previous Change Best Worst Trend
LCP Largest Contentful Paint 3.79 s — — 3.79 s 3.79 s
CLS Cumulative Layout Shift 0 — — 0 0
TBT Total Blocking Time 392 ms — — 392 ms 392 ms
FCP First Contentful Paint 2.52 s — — 2.52 s 2.52 s
Speed Index 2.52 s — — 2.52 s 2.52 s
TTFB Time to First Byte 487 ms — — 487 ms 487 ms

What LCP is made of

A flat LCP number tells you something regressed. The subparts tell you whether it was the server, resource discovery, the download, or rendering.

element render delay 129 ms
time to first byte 26 ms

Field data Chrome UX Report, origin-level

Real Chrome users, 28-day trailing window (2026-07-22 → 2026-08-18). This is what Google measures you on.

Metric p75 Rating Distribution (good / needs work / poor)
LCP CWV 951 ms good 95.9% good
CLS CWV 0 good 95% good
FCP 975 ms good 91.2% good
TTFB 519 ms good 90.9% good

Lab vs field

Lab LCP 3.79 s · field p75 951 ms · real users are 0.25× faster than the lab.

Field history 25 weeks

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

Week ending LCPINPCLSFCPTTFB
2026-08-15 932 ms — 0 939 ms 508 ms
2026-08-08 951 ms — 0 944 ms 537 ms
2026-08-01 898 ms — 0 897 ms 471 ms
2026-07-25 929 ms — 0 930 ms 540 ms
2026-07-18 1.09 s — 0 1.06 s 650 ms
2026-07-11 929 ms — 0 960 ms 609 ms
2026-07-04 957 ms — 0 1.05 s 707 ms
2026-06-27 1.01 s — 0 1.01 s 673 ms
2026-06-20 1.00 s — 0 1.05 s 673 ms
2026-06-13 990 ms — 0 1.00 s 632 ms
2026-06-06 964 ms — 0 1.00 s 598 ms
2026-05-30 1.01 s — 0 1.08 s 639 ms

Page weight

Metric Current Previous Change Best Worst Trend
Page Weight 2.39 MB — — 2.39 MB 2.39 MB
Requests 180 — — 180 180
Third-party Weight 378.0 kB — — 378.0 kB 378.0 kB
Third-party CPU 43 ms — — 43 ms 43 ms
Unused JS 248.8 kB — — 248.8 kB 248.8 kB
Unused CSS 32.9 kB — — 32.9 kB 32.9 kB

By resource type

image 1.54 MB · 129 req
script 526.0 kB · 11 req
other 137.8 kB · 28 req
font 123.8 kB · 5 req
document 64.4 kB · 1 req
third party 378.0 kB · 5 req

Third parties 5 entities

378.0 kB transferred, 43 ms of main thread time. This is the number most likely to regress without anyone on your team shipping anything.

Google CDN 344.0 kB · 29 ms CPU
Google Analytics 20.9 kB · 8 ms CPU
Cloudflare 11.5 kB · 3 ms CPU
Other Google APIs/SDKs 1.0 kB · 3 ms CPU
Cloudflare CDN 716 B · 0 ms CPU

Page health

Metric Current Previous Change Best Worst Trend
Main Thread Work 2.24 s — — 2.24 s 2.24 s
Long Tasks 4 — — 4 4
DOM Elements 674 — — 674 674
Axe Violations Violating nodes from a full axe run — stricter than Lighthouse's subset 7 — — 7 7
A11y Failures 2 — — 2 2
A11y Failing Nodes 6 — — 6 6

Main thread work

other 786 ms
script evaluation 637 ms
style layout 570 ms
script parse compile 122 ms
paint composite render 49 ms
parse HTML 40 ms
garbage collection 33 ms

Axe violations axe-core 4.13.0, full rule set

7 violating nodes across 3 rules, 948 passing. This is a standalone axe run, stricter than the subset Lighthouse folds into its score above — and it is the second tiebreaker in the ranking.

  • serious list — <ul> and <ol> must only directly contain <li>, <script> or <template> elements 5 nodes
  • critical aria-required-children — Certain ARIA roles must contain particular children 1 node
  • moderate region — All page content should be contained by landmarks 1 node

Accessibility failures 2 of 28 audits

Tracked as a count, not just the score — the weighted score is coarse enough that you can ship a broken component and barely move it.

  • list — Lists do not contain only `<li>` elements and script supporting elements (`<script>` and `<template>`). 5 nodes
  • aria-required-children — Elements with an ARIA `[role]` that require children to contain a specific `[role]` are missing some or all of those required children. 1 node

Hygiene

Changes rarely — which is exactly why a change is worth noticing.

HTTPS HSTS CSP Clickjacking protection Origin isolation Trusted Types bfcache h3 3 console errors

Measurement log

Every stored run for this URL, newest first. Failures are kept as records — "this site was down on Tuesday" is data too.

When PerfLCPCLSTBTWeight RunsSpreadBenchTook
Aug 20, 2026, 7:09 PM UTC 76 3.79 s 0 392 ms 2.39 MB 3/3 ±13 2,892 30s

Embed this score

Live below, then the markup that produces it. Drop that on any page to show covidtracking.com's scores, updated whenever this instance re-measures — more about the component. Don’t forget to bundle the speedlify-score.js component code into your site! 

<speedlify-score speedlify-url="https://zachleat.github.io/speedlify2/" url="https://covidtracking.com/"></speedlify-score>