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 ·

jekyllrb.com

https://jekyllrb.com/

99 93 100 100 ✓CWV 13AXE

Data from Aug 20, 2026, 11:32 PM UTC — 19h old.

Site Generators · 1 measurement · since Aug 20, 2026 · last attempt 19h

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.

Jekyll 4.4.1 Built with Jekyll 4.4.1
GitHub Pages Hosted by GitHub Pages

Core Web Vitals field data, url-level

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

LCP 1.08 s good
INP 75 ms good
CLS 0 good

Scores

99
Performance
no change
93
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 1.96 s — — 1.96 s 1.96 s
CLS Cumulative Layout Shift 0 — — 0 0
TBT Total Blocking Time 56 ms — — 56 ms 56 ms
FCP First Contentful Paint 902 ms — — 902 ms 902 ms
Speed Index 902 ms — — 902 ms 902 ms
TTFB Time to First Byte 602 ms — — 602 ms 602 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 70 ms
time to first byte 4 ms

Field data Chrome UX Report, url-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 1.08 s good 95.8% good
INP CWV Interaction to Next Paint — field only, Lighthouse cannot measure this in a lab run 75 ms good 97.4% good
CLS CWV 0 good 99.6% good
FCP 1.12 s good 90% good
TTFB 596 ms good 83% good

Lab vs field

Lab LCP 1.96 s · field p75 1.08 s · real users are 0.55× 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 1.08 s 76 ms 0 1.09 s 595 ms
2026-08-08 1.06 s 75 ms 0 1.07 s 548 ms
2026-08-01 1.03 s 76 ms 0 1.05 s 559 ms
2026-07-25 1.06 s 74 ms 0 1.08 s 609 ms
2026-07-18 1.08 s 73 ms 0 1.09 s 604 ms
2026-07-11 1.13 s 76 ms 0 1.15 s 638 ms
2026-07-04 1.16 s 73 ms 0 1.17 s 639 ms
2026-06-27 1.14 s 75 ms 0 1.14 s 622 ms
2026-06-20 1.14 s 74 ms 0 1.14 s 621 ms
2026-06-13 1.07 s 73 ms 0 1.07 s 609 ms
2026-06-06 1.05 s 72 ms 0 1.07 s 585 ms
2026-05-30 1.04 s 73 ms 0 1.05 s 585 ms

Page weight

Metric Current Previous Change Best Worst Trend
Page Weight 367.5 kB — — 367.5 kB 367.5 kB
Requests 12 — — 12 12
Third-party Weight 229.0 kB — — 229.0 kB 229.0 kB
Third-party CPU 63 ms — — 63 ms 63 ms
Unused JS 98.1 kB — — 98.1 kB 98.1 kB
Unused CSS 12.1 kB — — 12.1 kB 12.1 kB

By resource type

script 228.9 kB · 3 req
image 72.8 kB · 3 req
font 46.4 kB · 2 req
stylesheet 14.1 kB · 1 req
document 3.7 kB · 1 req
other 38 B · 1 req
third party 229.0 kB · 4 req

Third parties 3 entities

229.0 kB transferred, 63 ms of main thread time. This is the number most likely to regress without anyone on your team shipping anything.

Google Tag Manager 159.9 kB · 42 ms CPU
JSDelivr CDN 48.2 kB · 9 ms CPU
Google Analytics 20.9 kB · 12 ms CPU

Page health

Metric Current Previous Change Best Worst Trend
Main Thread Work 554 ms — — 554 ms 554 ms
Long Tasks 1 — — 1 1
DOM Elements 143 — — 143 143
Axe Violations Violating nodes from a full axe run — stricter than Lighthouse's subset 13 — — 13 13
A11y Failures 2 — — 2 2
A11y Failing Nodes 8 — — 8 8

Main thread work

script evaluation 280 ms
other 106 ms
style layout 86 ms
script parse compile 64 ms
parse HTML 12 ms
paint composite render 7 ms

Axe violations axe-core 4.13.0, full rule set

13 violating nodes across 4 rules, 232 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 link-in-text-block — Links must be distinguishable without relying on color 7 nodes
  • moderate region — All page content should be contained by landmarks 4 nodes
  • serious color-contrast — Elements must meet minimum color contrast ratio thresholds 1 node
  • moderate landmark-one-main — Document should have one main landmark 1 node

Accessibility failures 2 of 20 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.

  • link-in-text-block — Links rely on color to be distinguishable. 7 nodes
  • landmark-one-main — Document does not have a main landmark. 1 node

Hygiene

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

HTTPS HSTS CSP Clickjacking protection Origin isolation Trusted Types bfcache h2

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, 11:32 PM UTC 99 1.96 s 0 56 ms 367.5 kB 3/3 ±5 2,499 21.3s

Embed this score

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