nationalrail.co.uk

https://www.nationalrail.co.uk/

Ranks Overall #4 National Rail #1

Data from Oct 30, 2026, 10:10 PM UTC 48m 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

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

Stack

Built with Next.js

Uses React

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 20.77 s. Compare this filmstrip against another site.

2.60 s
3.09 s
7.79 s
10.39 s
11.61 s
12.98 s
15.58 s
18.18 s
20.77 s

Lighthouse Scores LAB Simulated

Performance

no change

Accessibility

no change

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), url-level.

Metric	Lab Simulated	Field
LCP CWV Largest Contentful Paint	8.71 s poor	— 8.71 s – 8.71 s	1.45 s good	88.5% 5.4% 6.1%
INP CWV Interaction to Next Paint — field only, no lab run can measure it	n/a	—	704 ms poor	13.3% 45.7% 41%
CLS CWV Cumulative Layout Shift	0.083 good	— 0.083 – 0.083	0.150 needs work	40.4% 47.7% 12%
TBT Total Blocking Time	575 ms needs work	— 575 ms – 575 ms	n/a	—
FCP First Contentful Paint	1.80 s good	— 1.80 s – 1.80 s	1.15 s good	86.3% 6.9% 6.8%
Speed Index	5.95 s poor	— 5.95 s – 5.95 s	n/a	—
TTFB Time to First Byte	666 ms good	— 666 ms – 666 ms	520 ms good	84.5% 10.1% 5.4%

Metric

Lab Simulated

Field

Value

Change / range

Trend

p75

Distribution

LCP CWV Largest Contentful Paint

8.71 s poor

— 8.71 s – 8.71 s

1.45 s good

88.5% 5.4% 6.1%

INP CWV Interaction to Next Paint — field only, no lab run can measure it

n/a

—

704 ms poor

13.3% 45.7% 41%

CLS CWV Cumulative Layout Shift

0.083 good

— 0.083 – 0.083

0.150 needs work

40.4% 47.7% 12%

TBT Total Blocking Time

575 ms needs work

— 575 ms – 575 ms

n/a

—

FCP First Contentful Paint

1.80 s good

— 1.80 s – 1.80 s

1.15 s good

86.3% 6.9% 6.8%

Speed Index

5.95 s poor

— 5.95 s – 5.95 s

n/a

—

TTFB Time to First Byte

666 ms good

— 666 ms – 666 ms

520 ms good

84.5% 10.1% 5.4%

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.

resource load duration 11.01 s

time to first byte 597 ms

element render delay 11 ms

LCP LAB Simulated vs LCP FIELD

Lab 8.71 s

Field p75 1.45 s

The lab LCP is 6.02× the field p75 — real users likely have above-average hardware or network connectivity.

Page weight

Metric	Value	Change / range
Page Weight	2.95 MB	— 2.95 MB – 2.95 MB
Requests	75	— 75 – 75
Third-party Weight	1.35 MB	— 1.35 MB – 1.35 MB
Third-party CPU	205 ms	— 205 ms – 205 ms
Unused JS	923 kB	— 923 kB – 923 kB
Unused CSS	12.6 kB	— 12.6 kB – 12.6 kB

Metric

Value

Change / range

Trend

Page Weight

2.95 MB

— 2.95 MB – 2.95 MB

Requests

— 75 – 75

Third-party Weight

1.35 MB

— 1.35 MB – 1.35 MB

Third-party CPU

205 ms

— 205 ms – 205 ms

Unused JS

923 kB

— 923 kB – 923 kB

Unused CSS

12.6 kB

— 12.6 kB – 12.6 kB

By resource type

Type	Share	Size	Requests
script	64.3%	1.89 MB	39
font	15.4%	453 kB	7
image	11.4%	335 kB	8
other	7.1%	210 kB	17
document	1.4%	39.9 kB	1
stylesheet	0.5%	15.0 kB	1
Total		2.95 MB	75

Third parties 8 entities

Entity	Transfer	Size	Main thread Simulated
Optanon	scriptother	347 kB	27 ms
Google/Doubleclick Ads	script	284 kB	29 ms
intergient.com	script	250 kB	29 ms
Google Tag Manager	script	198 kB	44 ms
confiant-integrations.net	script	170 kB	45 ms
All 8		1.35 MB	205 ms

Entity

Transfer

Size

Main thread Simulated

Optanon

scriptother

347 kB

27 ms

Google/Doubleclick Ads

script

284 kB

29 ms

intergient.com

script

250 kB

29 ms

Google Tag Manager

script

198 kB

44 ms

confiant-integrations.net

script

170 kB

45 ms

All 8

1.35 MB

205 ms

Without JavaScript

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

65.7% of pixels differ — the page changes substantially. A shifted layout counts as difference, so a <noscript> banner alone can account for a large figure.

Page health

Metric	Value	Change / range
Main Thread Work	2.65 s	— 2.65 s – 2.65 s
Long Tasks	11	— 11 – 11
DOM Elements	579	— 579 – 579
Axe Violations Violating nodes from a full Axe CLI run (more than Lighthouse reports)	4	— 4 – 4
A11y Failures	2	— 2 – 2
A11y Failing Nodes	12	— 12 – 12

Metric

Value

Change / range

Trend

Main Thread Work

2.65 s

— 2.65 s – 2.65 s

Long Tasks

— 11 – 11

DOM Elements

579

— 579 – 579

Axe Violations Violating nodes from a full Axe CLI run (more than Lighthouse reports)

— 4 – 4

A11y Failures

— 2 – 2

A11y Failing Nodes

— 12 – 12

Main thread work

Task	Share	Duration Simulated
script evaluation	58%	1.53 s
script parse compile	17%	453 ms
other	12%	317 ms
garbage collection	5%	145 ms
style layout	5%	142 ms
parse HTML	1%	37 ms
paint composite render	1%	31 ms
Total		2.65 s

Task

Time

Duration Simulated

script evaluation

58%

1.53 s

script parse compile

17%

453 ms

other

12%

317 ms

garbage collection

145 ms

style layout

142 ms

parse HTML

37 ms

paint composite render

31 ms

Total

2.65 s

Axe violations axe-core 4.13.0, full rule set

4 violating nodes across 2 rules, 1021 passing. This is a standalone Axe CLI run and is stricter than the subset Lighthouse already includes.

serious link-in-text-block — Links must be distinguishable without relying on color 3 nodes

Offending elements

.dHMYec.sc-7e26a0bc-1:nth-child(3) > .hLGUAO.sc-c449e399-0

<a class="sc-c449e399-0 hLGUAO" href="https://www.nationalrail.co.uk/disruptions/">Disruptions</a>

.dHMYec.sc-7e26a0bc-1:nth-child(4) > .hLGUAO.sc-c449e399-0:nth-child(1)

<a class="sc-c449e399-0 hLGUAO" href="https://www.nationalrail.co.uk/train-operator-status/">Status Updates</a>

.hLGUAO.sc-c449e399-0:nth-child(2)

<a class="sc-c449e399-0 hLGUAO" href="https://www.nationalrail.co.uk/engineering-works/">Engineering Works</a>

moderate region — All page content should be contained by landmarks 1 node
Offending element
1. #onetrust-consent-sdk
```
<div id="onetrust-consent-sdk" data-nosnippet="true">
```

Accessibility failures 2 of 29 audits

label-content-name-mismatch — Elements with visible text labels do not have matching accessible names. 9 nodes
link-in-text-block — Links rely on color to be distinguishable. 3 nodes

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 1 item
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 1 console error

Measurement log

Field history 25 weeks

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

Week ending	LCP	INP	CLS	FCP	TTFB
2026-10-24	1.45 s	702 ms	0.140	1.15 s	520 ms
2026-10-17	1.47 s	700 ms	0.130	1.14 s	521 ms
2026-10-10	1.47 s	694 ms	0.130	1.13 s	518 ms
2026-10-03	1.45 s	684 ms	0.130	1.12 s	515 ms
2026-09-26	1.41 s	683 ms	0.150	1.12 s	516 ms
2026-09-19	1.39 s	696 ms	0.190	1.13 s	530 ms
2026-09-12	1.37 s	711 ms	0.190	1.15 s	540 ms
2026-09-05	1.37 s	725 ms	0.190	1.15 s	544 ms
2026-08-29	1.37 s	735 ms	0.190	1.15 s	543 ms
2026-08-22	1.36 s	741 ms	0.190	1.14 s	532 ms
2026-08-15	1.34 s	742 ms	0.180	1.13 s	518 ms
2026-08-08	1.34 s	744 ms	0.180	1.13 s	509 ms

Week ending

LCP

INP

CLS

FCP

TTFB

2026-10-24

1.45 s

702 ms

0.140

1.15 s

520 ms

2026-10-17

1.47 s

700 ms

0.130

1.14 s

521 ms

2026-10-10

1.47 s

694 ms

0.130

1.13 s

518 ms

2026-10-03

1.45 s

684 ms

0.130

1.12 s

515 ms

2026-09-26

1.41 s

683 ms

0.150

1.12 s

516 ms

2026-09-19

1.39 s

696 ms

0.190

1.13 s

530 ms

2026-09-12

1.37 s

711 ms

0.190

1.15 s

540 ms

2026-09-05

1.37 s

725 ms

0.190

1.15 s

544 ms

2026-08-29

1.37 s

735 ms

0.190

1.15 s

543 ms

2026-08-22

1.36 s

741 ms

0.190

1.14 s

532 ms

2026-08-15

1.34 s

742 ms

0.180

1.13 s

518 ms

2026-08-08

1.34 s

744 ms

0.180

1.13 s

509 ms

Runs

Every stored run for this URL, newest first.

When	Scores	Perf	LCP	CLS	TBT	Weight	Runs	Spread	Bench	Took	Archive
Oct 30, 2026, 10:10 PM UTC		53	8.71 s	0.083	575 ms	2.95 MB	3/3	±1	2,050 -1%	78.1s	Wayback

When

Scores

Perf

LCP

CLS

TBT

Weight

Runs

Spread

Bench

Took

Stack

Filmstrip LAB 🐢 Throttled

Lighthouse Scores LAB 🤖 Simulated

Metrics LAB FIELD

LCP Subparts LAB 🐢 Throttled

LCP LAB 🤖 Simulated vs LCP FIELD

Page weight

By resource type

Third parties 8 entities

Without JavaScript

Page health

Main thread work

Axe violations axe-core 4.13.0, full rule set

Accessibility failures 2 of 29 audits

Best Practices failures 4 of 19 audits

Hygiene

Measurement log

Field history 25 weeks

Runs

Filmstrip LAB Throttled

Lighthouse Scores LAB Simulated

LCP Subparts LAB Throttled

LCP LAB Simulated vs LCP FIELD