lit.dev

Ranks Overall #906 Built Awesome #659 Developer Tooling #20 Frameworks and Libraries #4

Data from Oct 6, 2026, 1:02 PM UTC 44h old Measured every 2 days · 19 runs since Aug 21, 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 Lit 2.8.0

Hosted by Google Frontend

Filmstrip LAB Throttled

How the page drew during the measured load, at 8 points across 3.40 s. Compare this filmstrip against another site.

425 ms
795 ms
1.28 s
1.70 s
2.13 s
2.55 s
2.98 s
3.40 s

Lighthouse Scores LAB Simulated

Performance

↓ -1 (-1.2%)

100

Accessibility

no change

100

Best Practices

no change

100

SEO

no change

Metrics LAB FIELD

Core Web Vitals: passing 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), url-level.

Metric	Lab Simulated	Field
LCP CWV Largest Contentful Paint	4.13 s poor	↓ -1 ms 3.93 s – 4.14 s	1.85 s good	88.5% 8.6% 3%
INP CWV Interaction to Next Paint — field only, no lab run can measure it	n/a	—	68 ms good	98.4% 1.3% 0.4%
CLS CWV Cumulative Layout Shift	0.001 good	↑ +0.001 0 – 0.001	0 good	99.6% 0.4% 0%
TBT Total Blocking Time	125 ms good	↑ +9 ms (+7.8%) 49 ms – 176 ms	n/a	—
FCP First Contentful Paint	1.02 s good	→ no change 980 ms – 1.03 s	1.05 s good	89.9% 7.3% 2.9%
Speed Index	1.02 s good	→ no change 980 ms – 1.27 s	n/a	—
TTFB Time to First Byte	677 ms good	→ no change 625 ms – 691 ms	854 ms needs work	73.1% 21% 5.9%

Metric

Lab Simulated

Field

Value

Change / range

Trend

p75

Distribution

LCP CWV Largest Contentful Paint

4.13 s poor

↓ -1 ms 3.93 s – 4.14 s

1.85 s good

88.5% 8.6% 3%

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

n/a

—

68 ms good

98.4% 1.3% 0.4%

CLS CWV Cumulative Layout Shift

0.001 good

↑ +0.001 0 – 0.001

0 good

99.6% 0.4% 0%

TBT Total Blocking Time

125 ms good

↑ +9 ms (+7.8%) 49 ms – 176 ms

n/a

—

FCP First Contentful Paint

1.02 s good

→ no change 980 ms – 1.03 s

1.05 s good

89.9% 7.3% 2.9%

Speed Index

1.02 s good

→ no change 980 ms – 1.27 s

n/a

—

TTFB Time to First Byte

677 ms good

→ no change 625 ms – 691 ms

854 ms needs work

73.1% 21% 5.9%

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 2.45 s

time to first byte 642 ms

LCP LAB Simulated vs LCP FIELD

Lab 4.13 s

Field p75 1.85 s

The lab LCP is 2.24× the field p75 — real users likely have above-average hardware or network connectivity.

Page weight

Metric	Value	Change / range
Page Weight	519 kB	↓ -15 B 512 kB – 519 kB
Requests	35	→ no change 35 – 40
Third-party Weight	163 kB	↓ -19 B 156 kB – 163 kB
Third-party CPU	57 ms	↑ +1 ms (+1.1%) 38 ms – 67 ms
Unused JS	72.3 kB	↓ -866 B (-1.2%) 69.3 kB – 73.1 kB
Unused CSS	0 B	→ no change 0 B – 0 B

Metric

Value

Change / range

Trend

Page Weight

519 kB

↓ -15 B 512 kB – 519 kB

Requests

→ no change 35 – 40

Third-party Weight

163 kB

↓ -19 B 156 kB – 163 kB

Third-party CPU

57 ms

↑ +1 ms (+1.1%) 38 ms – 67 ms

Unused JS

72.3 kB

↓ -866 B (-1.2%) 69.3 kB – 73.1 kB

Unused CSS

0 B

→ no change 0 B – 0 B

By resource type

Type	Share	Size	Requests
font	55.6%	289 kB	8
script	39.2%	204 kB	17
document	3.6%	18.9 kB	1
image	0.9%	4.7 kB	5
other	0.7%	3.4 kB	4
Total		519 kB	35

Third parties 1 entities

Entity	Transfer	Size	Main thread Simulated
Google Tag Manager	script	163 kB	57 ms
Total		163 kB	57 ms

Entity

Transfer

Size

Main thread Simulated

Google Tag Manager

script

163 kB

57 ms

Total

163 kB

57 ms

Without JavaScript

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

17.4% 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
Main Thread Work	822 ms	↑ +9 ms (+1.1%) 689 ms – 1000 ms
Long Tasks	4	↑ +1 (+33.3%) 2 – 4
DOM Elements	904	→ no change 904 – 904
Axe Violations Violating nodes from a full Axe CLI run (more than Lighthouse reports)	5	→ no change 3 – 5
A11y Failures	1	→ no change 1 – 1
A11y Failing Nodes	1	→ no change 1 – 1

Metric

Value

Change / range

Trend

Main Thread Work

822 ms

↑ +9 ms (+1.1%) 689 ms – 1000 ms

Long Tasks

↑ +1 (+33.3%) 2 – 4

DOM Elements

904

→ no change 904 – 904

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

→ no change 3 – 5

A11y Failures

→ no change 1 – 1

A11y Failing Nodes

→ no change 1 – 1

Main thread work

Task	Share	Duration Simulated
script evaluation	37%	305 ms
other	29%	235 ms
style layout	19%	156 ms
script parse compile	6%	46 ms
parse HTML	5%	40 ms
paint composite render	5%	40 ms
Total		822 ms

Task

Time

Duration Simulated

script evaluation

37%

305 ms

other

29%

235 ms

style layout

19%

156 ms

script parse compile

46 ms

parse HTML

40 ms

paint composite render

40 ms

Total

822 ms

Axe violations axe-core 4.13.0, full rule set

5 violating nodes across 2 rules, 1005 passing. This is a standalone Axe CLI run and is stricter than the subset Lighthouse already includes.

moderate region — All page content should be contained by landmarks 3 nodes

Offending elements

litdev-cookie-banner .visually-hidden

<h2 class="visually-hidden">Cookies consent notice</h2>

litdev-cookie-banner .message

<div class="message">Lit.dev uses cookies from Google to deliver and enhance the quality of its services and to analyze traffic.</div>

litdev-cookie-banner litdev-ripple-icon-button:nth-child(1)

<litdev-ripple-icon-button href="https://policies.google.com/technologies/cookies">Learn more</litdev-ripple-icon-button>

serious scrollable-region-focusable — Scrollable region must have keyboard access 2 nodes
Offending elements
1. #tourTsCode > figure
```
<figure class="cm-editor">
```
2. #tourHtmlCode > figure
```
<figure class="cm-editor">
```

Accessibility failures 1 of 28 audits

label-content-name-mismatch — Elements with visible text labels do not have matching accessible names. 1 node

Hygiene

HTTPS HSTS CSP Clickjacking protection Origin isolation Trusted Types bfcache h2

Measurement log

Field history 25 weeks

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

Week ending	LCP	INP	FCP	TTFB
2026-09-26	1.89 s	70 ms	1.06 s	829 ms
2026-09-19	1.90 s	71 ms	1.05 s	843 ms
2026-09-12	1.92 s	72 ms	1.06 s	859 ms
2026-09-05	1.97 s	67 ms	1.05 s	824 ms
2026-08-29	1.89 s	68 ms	1.02 s	829 ms
2026-08-22	1.88 s	68 ms	988 ms	783 ms
2026-08-15	1.93 s	71 ms	994 ms	751 ms
2026-08-08	1.77 s	74 ms	993 ms	752 ms
2026-08-01	1.74 s	74 ms	976 ms	735 ms
2026-07-25	1.85 s	77 ms	1.05 s	788 ms
2026-07-18	1.85 s	78 ms	1.05 s	787 ms
2026-07-11	1.88 s	74 ms	1.04 s	779 ms

Week ending

LCP

INP

CLS

FCP

TTFB

2026-09-26

1.89 s

70 ms

1.06 s

829 ms

2026-09-19

1.90 s

71 ms

1.05 s

843 ms

2026-09-12

1.92 s

72 ms

1.06 s

859 ms

2026-09-05

1.97 s

67 ms

1.05 s

824 ms

2026-08-29

1.89 s

68 ms

1.02 s

829 ms

2026-08-22

1.88 s

68 ms

988 ms

783 ms

2026-08-15

1.93 s

71 ms

994 ms

751 ms

2026-08-08

1.77 s

74 ms

993 ms

752 ms

2026-08-01

1.74 s

74 ms

976 ms

735 ms

2026-07-25

1.85 s

77 ms

1.05 s

788 ms

2026-07-18

1.85 s

78 ms

1.05 s

787 ms

2026-07-11

1.88 s

74 ms

1.04 s

779 ms

Runs

Every stored run for this URL, newest first.

When	Perf	LCP	CLS	TBT	Weight	Runs	Spread	Bench	Took	Archive
Oct 6, 2026, 1:02 PM UTC	85	4.13 s	0.001	125 ms	519 kB	3/3	±2	2,434 -2%	51.4s	Wayback
Oct 1, 2026, 8:31 PM UTC	86	4.13 s	0	116 ms	519 kB	3/3	±2	2,494 0%	52.3s	Wayback
Sep 29, 2026, 6:09 PM UTC	87	3.97 s	0	122 ms	518 kB	3/3	±4	2,463 -1%	52.5s	Wayback
Sep 26, 2026, 6:46 PM UTC	86	3.94 s	0	146 ms	517 kB	3/3	±3	2,491 0%	51.9s	Wayback
Sep 24, 2026, 7:38 AM UTC	86	4.09 s	0.001	129 ms	517 kB	3/3	±3	2,423 -3%	51.6s	Wayback
Sep 22, 2026, 3:56 AM UTC	86	4.12 s	0	81 ms	516 kB	3/3	±3	3,059 +23%	49.6s	Wayback
Sep 19, 2026, 4:28 PM UTC	86	4.14 s	0.001	95 ms	516 kB	3/3	±1	2,303 -7%	52.5s	Wayback
Sep 17, 2026, 12:15 AM UTC	86	4.14 s	0	113 ms	516 kB	3/3	±3	2,490 0%	52.8s	Wayback
Sep 14, 2026, 10:09 PM UTC	87	3.95 s	0.001	97 ms	516 kB	3/3	±2	2,254 -9%	52.5s	Wayback
Sep 12, 2026, 7:21 AM UTC	85	3.93 s	0	176 ms	516 kB	3/3	±3	2,437 -2%	54s	Wayback
Sep 10, 2026, 5:57 AM UTC	87	4.10 s	0.001	49 ms	516 kB	3/3	±1	3,428 +38%	23.4s	Wayback
Sep 8, 2026, 5:37 AM UTC	86	3.95 s	0	151 ms	516 kB	3/3	±6	2,329 -6%	26.3s	Wayback
Sep 6, 2026, 12:57 AM UTC	87	3.97 s	0	109 ms	516 kB	3/3	±2	2,473 -1%	26s	Wayback
Sep 4, 2026, 6:28 PM UTC	87	3.95 s	0	95 ms	513 kB	3/3	±3	1,544 -38%	24.9s	Wayback
Sep 3, 2026, 7:11 AM UTC	86	3.97 s	0	127 ms	514 kB	3/3	±4	1,493 -40%	25.6s	Wayback
Sep 1, 2026, 11:45 PM UTC	87	4.10 s	0.001	60 ms	514 kB	3/3	±1	3,302 +33%	23.9s	Wayback
Aug 31, 2026, 10:51 PM UTC	86	4.14 s	0.001	102 ms	513 kB	3/3	±3	2,446 -2%	26.1s	Wayback
Aug 29, 2026, 7:41 PM UTC	87	3.95 s	0	91 ms	513 kB	3/3	±2	2,299 -8%	24.2s	Wayback
Aug 21, 2026, 3:10 AM UTC	87	3.98 s	0	100 ms	512 kB	3/3	±2	2,475 0%	24.4s	Wayback

When

Scores

Perf

LCP

CLS

TBT

Weight

Runs

Spread

Bench

Took

Embed this score

Use this web component to show lit.dev's scores on any website, updated whenever this instance re-measures. Don’t forget to bundle the speedlify2-score.js component code into your site!

<speedlify2-score speedlify-url="https://www.speedlify.dev/" url="https://lit.dev/"></speedlify2-score>

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 1 entities

Without JavaScript

Page health

Main thread work

Axe violations axe-core 4.13.0, full rule set

Accessibility failures 1 of 28 audits

Hygiene

Measurement log

Field history 25 weeks

Runs

Embed this score

Filmstrip LAB Throttled

Lighthouse Scores LAB Simulated

LCP Subparts LAB Throttled

LCP LAB Simulated vs LCP FIELD