github.com/lit/lit-element-starter-ts

https://github.com/lit/lit-element-starter-ts

Ranks Overall #1,296 Built Awesome #886

Data from Oct 7, 2026, 2:23 AM UTC 30h old Measured once a week · 9 runs since Aug 20, 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

Uses ReactLit 1.1.2

Hosted by GitHub Pages

Lighthouse Scores LAB Simulated

Performance

↓ -5 (-9.8%)

Accessibility

no change

Best Practices

↓ -4 (-4%)

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 (2026-09-07 → 2026-10-04), origin-level.

Metric	Lab Simulated	Field
LCP CWV Largest Contentful Paint	11.67 s poor	↑ +377 ms (+3.3%) 9.65 s – 11.67 s	2.32 s good	78.3% 13.2% 8.5%
INP CWV Interaction to Next Paint — field only, no lab run can measure it	n/a	—	262 ms needs work	67.7% 23.4% 8.9%
CLS CWV Cumulative Layout Shift	0 good	↓ -0.002 (-100%) significant 0 – 0.004	0.040 good	86.8% 6.4% 6.8%
TBT Total Blocking Time	394 ms needs work	↑ +152 ms (+62.8%) 197 ms – 445 ms	n/a	—
FCP First Contentful Paint	10.46 s poor	↓ -73 ms (-0.7%) 8.90 s – 10.54 s	2.03 s needs work	68.4% 20.5% 11.1%
Speed Index	10.46 s poor	↓ -73 ms (-0.7%) 8.90 s – 10.54 s	n/a	—
TTFB Time to First Byte	606 ms good	↓ -46 ms (-7.1%) significant 604 ms – 652 ms	1.21 s needs work	45.9% 43.6% 10.5%

Metric

Lab Simulated

Field

Value

Change / range

Trend

p75

Distribution

LCP CWV Largest Contentful Paint

11.67 s poor

↑ +377 ms (+3.3%) 9.65 s – 11.67 s

2.32 s good

78.3% 13.2% 8.5%

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

n/a

—

262 ms needs work

67.7% 23.4% 8.9%

CLS CWV Cumulative Layout Shift

0 good

↓ -0.002 (-100%) significant 0 – 0.004

0.040 good

86.8% 6.4% 6.8%

TBT Total Blocking Time

394 ms needs work

↑ +152 ms (+62.8%) 197 ms – 445 ms

n/a

—

FCP First Contentful Paint

10.46 s poor

↓ -73 ms (-0.7%) 8.90 s – 10.54 s

2.03 s needs work

68.4% 20.5% 11.1%

Speed Index

10.46 s poor

↓ -73 ms (-0.7%) 8.90 s – 10.54 s

n/a

—

TTFB Time to First Byte

606 ms good

↓ -46 ms (-7.1%) significant 604 ms – 652 ms

1.21 s needs work

45.9% 43.6% 10.5%

LCP Subparts LAB Unthrottled

The subparts attribute LCP to your server, resource discovery, download, or rendering. Note that the Lab LCP shown above is a simulated throttled estimate.

element render delay 420 ms

time to first byte 8 ms

LCP LAB Simulated vs LCP FIELD

Lab 11.67 s

Field p75 2.32 s

The lab LCP is 5.03× the field p75 — real users likely have above-average hardware or network connectivity.

Page weight

Metric	Value	Change / range
Page Weight	2.20 MB	↑ +77.4 kB (+3.7%) 1.81 MB – 2.20 MB
Requests	189	↑ +17 (+9.9%) significant 154 – 189
Third-party Weight	2.06 MB	↑ +74.5 kB (+3.9%) 1.66 MB – 2.06 MB
Third-party CPU	290 ms	↑ +89 ms (+44.4%) 160 ms – 290 ms
Unused JS	402 kB	↓ -6.2 kB (-1.6%) 373 kB – 410 kB
Unused CSS	199 kB	↑ +3.4 kB (+1.8%) 156 kB – 199 kB

Metric

Value

Change / range

Trend

Page Weight

2.20 MB

↑ +77.4 kB (+3.7%) 1.81 MB – 2.20 MB

Requests

189

↑ +17 (+9.9%) significant 154 – 189

Third-party Weight

2.06 MB

↑ +74.5 kB (+3.9%) 1.66 MB – 2.06 MB

Third-party CPU

290 ms

↑ +89 ms (+44.4%) 160 ms – 290 ms

Unused JS

402 kB

↓ -6.2 kB (-1.6%) 373 kB – 410 kB

Unused CSS

199 kB

↑ +3.4 kB (+1.8%) 156 kB – 199 kB

By resource type

Type	Share	Size	Requests
script	78.9%	1.73 MB	135
stylesheet	13.9%	305 kB	26
other	2.6%	57.9 kB	14
document	2.4%	53.0 kB	1
image	2.2%	48.3 kB	13
Total		2.20 MB	189

Third parties 1 entities

Entity	Transfer	Size	Main thread Simulated
githubassets.com	script	2.06 MB	290 ms
Total		2.06 MB	290 ms

Entity

Transfer

Size

Main thread Simulated

githubassets.com

script

2.06 MB

290 ms

Total

2.06 MB

290 ms

Page health

Metric	Value	Change / range
Main Thread Work	6.49 s	↑ +1896 ms (+41.3%) 3.98 s – 6.49 s
Long Tasks	14	↑ +2 (+16.7%) 12 – 18
DOM Elements	1,791	↑ +65 (+3.8%) 1,726 – 1,791
Axe Violations Violating nodes from a full Axe CLI run (more than Lighthouse reports)	0	→ no change 0 – 0
A11y Failures	2	↑ +1 (+100%) significant 1 – 2
A11y Failing Nodes	11	↑ +2 (+22.2%) significant 9 – 11

Metric

Value

Change / range

Trend

Main Thread Work

6.49 s

↑ +1896 ms (+41.3%) 3.98 s – 6.49 s

Long Tasks

↑ +2 (+16.7%) 12 – 18

DOM Elements

1,791

↑ +65 (+3.8%) 1,726 – 1,791

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

→ no change 0 – 0

A11y Failures

↑ +1 (+100%) significant 1 – 2

A11y Failing Nodes

↑ +2 (+22.2%) significant 9 – 11

Main thread work

Task	Share	Duration Simulated
style layout	33%	2.16 s
script evaluation	32%	2.07 s
other	28%	1.81 s
parse HTML	3%	197 ms
paint composite render	3%	183 ms
garbage collection	1%	59 ms
script parse compile	0%	14 ms
Total		6.49 s

Task

Time

Duration Simulated

style layout

33%

2.16 s

script evaluation

32%

2.07 s

other

28%

1.81 s

parse HTML

197 ms

paint composite render

183 ms

garbage collection

59 ms

script parse compile

14 ms

Total

6.49 s

Axe violations axe-core 4.13.0, full rule set

0 violating nodes across 0 rules, 1901 passing. This is a standalone Axe CLI run and is stricter than the subset Lighthouse already includes.

Accessibility failures 2 of 32 audits

target-size — Touch targets do not have sufficient size or spacing. 9 nodes
label-content-name-mismatch — Elements with visible text labels do not have matching accessible names. 2 nodes

Best Practices failures 1 of 18 audits

errors-in-console — Browser errors were logged to the console 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
2026-09-26	2.29 s	262 ms	0.030	2.02 s	1.21 s
2026-09-19	2.28 s	261 ms	0.020	2.01 s	1.20 s
2026-09-12	2.26 s	257 ms	0.020	2.00 s	1.20 s
2026-09-05	2.25 s	252 ms	0.020	1.99 s	1.19 s
2026-08-29	2.22 s	246 ms	0.020	1.95 s	1.18 s
2026-08-22	2.20 s	243 ms	0.020	1.92 s	1.17 s
2026-08-15	2.19 s	243 ms	0.020	1.89 s	1.17 s
2026-08-08	2.18 s	244 ms	0.020	1.87 s	1.17 s
2026-08-01	2.17 s	246 ms	0.020	1.85 s	1.17 s
2026-07-25	2.16 s	247 ms	0.020	1.84 s	1.16 s
2026-07-18	2.15 s	248 ms	0.030	1.85 s	1.17 s
2026-07-11	2.17 s	248 ms	0.030	1.86 s	1.18 s

Week ending

LCP

INP

CLS

FCP

TTFB

2026-09-26

2.29 s

262 ms

0.030

2.02 s

1.21 s

2026-09-19

2.28 s

261 ms

0.020

2.01 s

1.20 s

2026-09-12

2.26 s

257 ms

0.020

2.00 s

1.20 s

2026-09-05

2.25 s

252 ms

0.020

1.99 s

1.19 s

2026-08-29

2.22 s

246 ms

0.020

1.95 s

1.18 s

2026-08-22

2.20 s

243 ms

0.020

1.92 s

1.17 s

2026-08-15

2.19 s

243 ms

0.020

1.89 s

1.17 s

2026-08-08

2.18 s

244 ms

0.020

1.87 s

1.17 s

2026-08-01

2.17 s

246 ms

0.020

1.85 s

1.17 s

2026-07-25

2.16 s

247 ms

0.020

1.84 s

1.16 s

2026-07-18

2.15 s

248 ms

0.030

1.85 s

1.17 s

2026-07-11

2.17 s

248 ms

0.030

1.86 s

1.18 s

Runs

Every stored run for this URL, newest first.

When Scores Perf LCP CLS TBT Weight Runs Spread Bench Took Archive

Oct 7, 2026, 2:23 AM UTC 46 11.67 s 0 394 ms 2.20 MB 3/3 ±3 2,477 0% 69.5s Wayback

Oct 6, 2026, 12:56 PM UTC TRACING_ALREADY_STARTED: An internal Chrome error occurred. Please restart Chrome and try re-running Lighthouse. 56.8s

Sep 29, 2026, 11:16 AM UTC 51 11.29 s 0.002 242 ms 2.12 MB 3/3 ±2 2,990 +20% 58.1s Wayback

Sep 22, 2026, 9:13 AM UTC 53 11.24 s 0.002 197 ms 2.12 MB 3/3 ±3 4,039 +62% 49.6s Wayback

Sep 15, 2026, 6:06 AM UTC 47 11.17 s 0.002 369 ms 2.12 MB 3/3 ±1 2,473 -1% 65.5s Wayback

Sep 8, 2026, 5:38 AM UTC 52 9.81 s 0.004 235 ms 1.83 MB 3/3 ±11 3,416 +37% 54.2s Wayback

Sep 1, 2026, 1:41 AM UTC 46 9.82 s 0.002 428 ms 1.83 MB 3/3 ±6 2,474 -1% 67.1s Wayback

Aug 29, 2026, 6:00 AM UTC TRACING_ALREADY_STARTED: An internal Chrome error occurred. Please restart Chrome and try re-running Lighthouse. 54.4s

Aug 20, 2026, 11:27 PM UTC 45 9.65 s 0.002 445 ms 1.81 MB 3/3 ±13 2,492 0% 66.2s Wayback

When	Perf	LCP	CLS	TBT	Weight	Runs	Spread	Bench	Took	Archive
Oct 7, 2026, 2:23 AM UTC	46	11.67 s	0	394 ms	2.20 MB	3/3	±3	2,477 0%	69.5s	Wayback
Oct 6, 2026, 12:56 PM UTC	`TRACING_ALREADY_STARTED: An internal Chrome error occurred. Please restart Chrome and try re-running Lighthouse.`	56.8s
Sep 29, 2026, 11:16 AM UTC	51	11.29 s	0.002	242 ms	2.12 MB	3/3	±2	2,990 +20%	58.1s	Wayback
Sep 22, 2026, 9:13 AM UTC	53	11.24 s	0.002	197 ms	2.12 MB	3/3	±3	4,039 +62%	49.6s	Wayback
Sep 15, 2026, 6:06 AM UTC	47	11.17 s	0.002	369 ms	2.12 MB	3/3	±1	2,473 -1%	65.5s	Wayback
Sep 8, 2026, 5:38 AM UTC	52	9.81 s	0.004	235 ms	1.83 MB	3/3	±11	3,416 +37%	54.2s	Wayback
Sep 1, 2026, 1:41 AM UTC	46	9.82 s	0.002	428 ms	1.83 MB	3/3	±6	2,474 -1%	67.1s	Wayback
Aug 29, 2026, 6:00 AM UTC	`TRACING_ALREADY_STARTED: An internal Chrome error occurred. Please restart Chrome and try re-running Lighthouse.`	54.4s
Aug 20, 2026, 11:27 PM UTC	45	9.65 s	0.002	445 ms	1.81 MB	3/3	±13	2,492 0%	66.2s	Wayback

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Stack

Lighthouse Scores LAB 🤖 Simulated

Metrics LAB FIELD

LCP Subparts LAB 🐇 Unthrottled

LCP LAB 🤖 Simulated vs LCP FIELD

Page weight

By resource type

Third parties 1 entities

Page health

Main thread work

Axe violations axe-core 4.13.0, full rule set

Accessibility failures 2 of 32 audits

Best Practices failures 1 of 18 audits

Hygiene

Measurement log

Field history 25 weeks

Runs

Embed this score

Lighthouse Scores LAB Simulated

LCP Subparts LAB Unthrottled

LCP LAB Simulated vs LCP FIELD