speedlify2

Lighthouse lab metrics, Axe, and Chrome UX Report field data for a list of sites recorded and compared over time. Follow us on Mastodon or Bluesky.

Charts Compare Measurement runs Embed a score Open to Work

nationalrail.co.uk/journey-planner?adults=1&destination=MAN&extraTime=0&leavingDate=141126&leavingHour=10&leavingMin=00&leavingType=departing&origin=BTN&type=single

https://www.nationalrail.co.uk/journey-planner?adults=1&destination=MAN&extraTime=0&leavingDate=141126&leavingHour=10&leavingMin=00&leavingType=departing&origin=BTN&type=single

46PERF 100A11Y 73BEST 100SEO !AXE ✗CWV

Ranks Overall #6 National Rail #2

Data from Oct 30, 2026, 10:17 PM UTC old Measured once a day · 1 run since Oct 30, 2026

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

This URL redirects to https://www.nationalrail.co.uk/journey-planner/?adults=1&destination=MAN&extraTime=0&leavingDate=141126&leavingHour=10&leavingMin=00&leavingType=departing&origin=BTN&type=single.

The same URL in a different form — a trailing slash — so both are treated as one site rather than two: one history, measured once. Lighthouse follows the redirect, so the numbers below describe the page actually served; the only cost is an extra hop on each run.

Lab data is measured using Lighthouse, Mobile mode unless otherwise specified. Field data is reported from Chrome UX Report (using p75 measurements).

Stack

Next.js Built with Next.js
Uses ReactReact
Cloudflare Hosted by Cloudflare
Rendered On each request getServerSideProps in __NEXT_DATA__

Filmstrip LAB Throttled

How the page drew during the measured load, at 9 points across 20.40 s. Compare this filmstrip against another site.

  1. 2.55 s
  2. 3.72 s
  3. 7.65 s
  4. 10.20 s
  5. 12.75 s
  6. 15.30 s
  7. 17.85 s
  8. 19.36 s
  9. 20.40 s

Lighthouse Scores LAB Simulated

46
Performance
no change
100
Accessibility
no change
73
Best Practices
no change
100
SEO
no change

Metrics LAB FIELD

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

Field figures are the p75 across real Chrome users over a 28-day trailing window (2026-10-01 → 2026-10-28), origin-level.

Metric Lab Simulated Field
Value Change / range Trend p75 Distribution
LCP CWV Largest Contentful Paint 17.65 s poor — 17.65 s – 17.65 s 2.32 s good 77.1% 11% 11.9%
INP CWV Interaction to Next Paint — field only, no lab run can measure it n/a — 540 ms poor 33.4% 38.9% 27.6%
CLS CWV Cumulative Layout Shift 0.085 good — 0.085 – 0.085 0.180 needs work 50.6% 30.2% 19.2%
TBT Total Blocking Time 811 ms poor — 811 ms – 811 ms n/a —
FCP First Contentful Paint 1.89 s needs work — 1.89 s – 1.89 s 1.52 s good 81% 10.6% 8.4%
Speed Index 6.88 s poor — 6.88 s – 6.88 s n/a —
TTFB Time to First Byte 504 ms good — 504 ms – 504 ms 955 ms needs work 68.8% 21.4% 9.8%

LCP Subparts LAB Throttled

The subparts attribute LCP to your server, resource discovery, download, or rendering. They come from one throttled load, the same one as the filmstrip, so they add up to that load’s LCP rather than the simulated Lab LCP above.

element render delay 17.67 s
time to first byte 1.69 s

LCP LAB Simulated vs LCP FIELD

Lab 17.65 s
Field p75 2.32 s

The lab LCP is 7.61× the field p75 — real users likely have above-average hardware or network connectivity.

Page weight

Metric Value Change / range Trend
Page Weight 2.77 MB — 2.77 MB – 2.77 MB
Requests 91 — 91 – 91
Third-party Weight 1.35 MB — 1.35 MB – 1.35 MB
Third-party CPU 191 ms — 191 ms – 191 ms
Unused JS 953 kB — 953 kB – 953 kB
Unused CSS 12.6 kB — 12.6 kB – 12.6 kB

By resource type

Type Transfer Share Size Requests
script 70.6% 1.96 MB 46
font 16.3% 453 kB 7
other 10.2% 283 kB 28
document 1.4% 38.3 kB 1
image 0.9% 25.6 kB 6
stylesheet 0.5% 15.0 kB 1
Total 2.77 MB 91

Third parties 8 entities

Entity Transfer Size Main thread Simulated
Optanon scriptother 347 kB 23 ms
Google/Doubleclick Ads script 285 kB 29 ms
intergient.com script 250 kB 29 ms
Google Tag Manager script 198 kB 37 ms
confiant-integrations.net script 169 kB 52 ms
All 8 1.35 MB 191 ms

Without JavaScript

This page is client rendered.

Nothing was painted until the scripts ran. This is a web performance and robustness issue!

The same load, photographed twice at 412×823: once with scripts disabled, once as rendered.

Scripts disabled
As rendered

34.3% of pixels differ — parts of the page change. A shifted layout counts as difference, so a <noscript> banner alone can account for a large figure.

Page health

Metric Value Change / range Trend
Main Thread Work 3.85 s — 3.85 s – 3.85 s
Long Tasks 11 — 11 – 11
DOM Elements 1,131 — 1,131 – 1,131
Axe Violations Violating nodes from a full Axe CLI run (more than Lighthouse reports) 1 — 1 – 1
A11y Failures 0 — 0 – 0
A11y Failing Nodes 0 — 0 – 0

Main thread work

Task Time Share Duration Simulated
script evaluation 47% 1.81 s
other 21% 812 ms
script parse compile 12% 454 ms
paint composite render 10% 377 ms
style layout 7% 261 ms
garbage collection 3% 108 ms
parse HTML 1% 35 ms
Total 3.85 s

Axe violations axe-core 4.13.0, full rule set

1 violating node across 1 rule, 2014 passing. This is a standalone Axe CLI run and is stricter than the subset Lighthouse already includes.

Best Practices failures 4 of 19 audits

  • third-party-cookies — Uses third-party cookies 1 item
  • errors-in-console — Browser errors were logged to the console 2 items
  • inspector-issues — Issues were logged in the `Issues` panel in Chrome Devtools 2 items
  • valid-source-maps — Missing source maps for large first-party JavaScript 1 item

Hygiene

HTTPS HSTS CSP Clickjacking protection Origin isolation Trusted Types bfcache h2 2 console errors

Measurement log

Every stored run for this URL, newest first.

When Scores PerfLCPCLSTBTWeight RunsSpreadBenchTook Archive
Oct 30, 2026, 10:17 PM UTC 46 17.65 s 0.085 811 ms 2.77 MB 3/3 ±1 2,072 0% 81.1s Wayback