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 ·

undefinednull.com

https://www.undefinednull.com/

Data from Aug 21, 2026, 2:40 PM UTC — 3h old.

Built Awesome · 1 measurement · since Aug 21, 2026 · last attempt 3h

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.

GitHub Pages Hosted by GitHub Pages

Scores

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

Lab metrics Lighthouse, mobile

Metric Current Previous Change Best Worst Trend
LCP Largest Contentful Paint 984 ms — — 984 ms 984 ms
CLS Cumulative Layout Shift 0 — — 0 0
TBT Total Blocking Time 65 ms — — 65 ms 65 ms
FCP First Contentful Paint 984 ms — — 984 ms 984 ms
Speed Index 984 ms — — 984 ms 984 ms
TTFB Time to First Byte 490 ms — — 490 ms 490 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.

time to first byte 44 ms
element render delay 40 ms

Page weight

Metric Current Previous Change Best Worst Trend
Page Weight 1.13 MB — — 1.13 MB 1.13 MB
Requests 39 — — 39 39
Third-party Weight 206.9 kB — — 206.9 kB 206.9 kB
Third-party CPU 62 ms — — 62 ms 62 ms
Unused JS 78.8 kB — — 78.8 kB 78.8 kB
Unused CSS 12.7 kB — — 12.7 kB 12.7 kB

By resource type

other 877.1 kB · 34 req
script 206.8 kB · 3 req
document 33.1 kB · 1 req
third party 206.9 kB · 4 req

Third parties 3 entities

206.9 kB transferred, 62 ms of main thread time. This is the number most likely to regress without anyone on your team shipping anything.

Google Tag Manager 174.5 kB · 44 ms CPU
Google Analytics 20.9 kB · 15 ms CPU
Cloudflare 11.5 kB · 4 ms CPU

Page health

Metric Current Previous Change Best Worst Trend
Main Thread Work 565 ms — — 565 ms 565 ms
Long Tasks 3 — — 3 3
DOM Elements 192 — — 192 192
Axe Violations Violating nodes from a full axe run — stricter than Lighthouse's subset 0 — — 0 0
A11y Failures 0 — — 0 0
A11y Failing Nodes 0 — — 0 0

Main thread work

script evaluation 275 ms
other 113 ms
style layout 79 ms
script parse compile 63 ms
paint composite render 14 ms
parse HTML 13 ms
garbage collection 9 ms

Axe violations axe-core 4.13.0, full rule set

0 violating nodes across 0 rules, 405 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.

Hygiene

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

HTTPS HSTS CSP Clickjacking protection Origin isolation Trusted Types bfcache h3

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 21, 2026, 2:40 PM UTC 100 984 ms 0 65 ms 1.13 MB 3/3 ±0 2,354 25.1s

Embed this score

Live below, then the markup that produces it. Drop that on any page to show undefinednull.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://www.undefinednull.com/"></speedlify-score>