docs.flutter.dev

https://docs.flutter.dev/

Ranks Overall #995 Built Awesome #715

Data from Oct 3, 2026, 1:11 PM UTC 4d old Measured once a week · 7 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).

Lighthouse Scores LAB Simulated

Performance

↓ -18 (-20.2%)

Accessibility

no change

100

Best Practices

↑ +23 (+29.9%)

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 (2026-09-04 → 2026-10-01), url-level.

Metric	Lab Simulated	Field
LCP CWV Largest Contentful Paint	5.29 s poor	↑ +3131 ms (+145.1%) significant 1.99 s – 5.29 s	1.37 s good	89.2% 5.8% 5%
INP CWV Interaction to Next Paint — field only, no lab run can measure it	n/a	—	150 ms good	85.1% 12.8% 2.1%
CLS CWV Cumulative Layout Shift	0.029 good	→ no change 0.007 – 0.029	0 good	98.1% 1% 0.9%
TBT Total Blocking Time	347 ms needs work	↓ -16 ms (-4.4%) 214 ms – 378 ms	n/a	—
FCP First Contentful Paint	1.83 s needs work	↓ -36 ms (-1.9%) 1.83 s – 2.90 s	1.23 s good	83.9% 8.7% 7.5%
Speed Index	1.83 s good	↓ -36 ms (-1.9%) 1.83 s – 2.90 s	n/a	—
TTFB Time to First Byte	609 ms good	↓ -9 ms (-1.5%) 609 ms – 621 ms	663 ms good	80.3% 12.6% 7.2%

Metric

Lab Simulated

Field

Value

Change / range

Trend

p75

Distribution

LCP CWV Largest Contentful Paint

5.29 s poor

↑ +3131 ms (+145.1%) significant 1.99 s – 5.29 s

1.37 s good

89.2% 5.8% 5%

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

n/a

—

150 ms good

85.1% 12.8% 2.1%

CLS CWV Cumulative Layout Shift

0.029 good

→ no change 0.007 – 0.029

0 good

98.1% 1% 0.9%

TBT Total Blocking Time

347 ms needs work

↓ -16 ms (-4.4%) 214 ms – 378 ms

n/a

—

FCP First Contentful Paint

1.83 s needs work

↓ -36 ms (-1.9%) 1.83 s – 2.90 s

1.23 s good

83.9% 8.7% 7.5%

Speed Index

1.83 s good

↓ -36 ms (-1.9%) 1.83 s – 2.90 s

n/a

—

TTFB Time to First Byte

609 ms good

↓ -9 ms (-1.5%) 609 ms – 621 ms

663 ms good

80.3% 12.6% 7.2%

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 128 ms

time to first byte 5 ms

LCP LAB Simulated vs LCP FIELD

Lab 5.29 s

Field p75 1.37 s

The lab LCP is 3.85× the field p75 — real users likely have above-average hardware or network connectivity.

Page weight

Metric	Value	Change / range
Page Weight	1.20 MB	↓ -780 B (-0.1%) 1.18 MB – 1.20 MB
Requests	71	↓ -1 (-1.4%) 71 – 77
Third-party Weight	1.01 MB	↓ -849 B (-0.1%) 988 kB – 1.01 MB
Third-party CPU	158 ms	↓ -5 ms (-3.3%) 116 ms – 163 ms
Unused JS	176 kB	↑ +1.4 kB (+0.8%) 149 kB – 176 kB
Unused CSS	11.8 kB	↓ -8 B (-0.1%) 0 B – 11.8 kB

Metric

Value

Change / range

Trend

Page Weight

1.20 MB

↓ -780 B (-0.1%) 1.18 MB – 1.20 MB

Requests

↓ -1 (-1.4%) 71 – 77

Third-party Weight

1.01 MB

↓ -849 B (-0.1%) 988 kB – 1.01 MB

Third-party CPU

158 ms

↓ -5 ms (-3.3%) 116 ms – 163 ms

Unused JS

176 kB

↑ +1.4 kB (+0.8%) 149 kB – 176 kB

Unused CSS

11.8 kB

↓ -8 B (-0.1%) 0 B – 11.8 kB

By resource type

Type	Share	Size	Requests
font	45.6%	548 kB	2
script	39.1%	470 kB	39
image	8.7%	105 kB	11
other	3.5%	41.9 kB	13
stylesheet	1.6%	19.4 kB	4
document	1.4%	17.0 kB	1
Total		1.20 MB	71

Third parties 7 entities

Entity	Transfer	Size	Main thread Simulated
Google Fonts	font	551 kB	0 ms
Google Tag Manager	script	326 kB	151 ms
YouTube	image	101 kB	0 ms
Google CDN		30.4 kB	6 ms
JSDelivr CDN		3.7 kB	1 ms
All 7		1.01 MB	158 ms

Entity

Transfer

Size

Main thread Simulated

Google Fonts

font

551 kB

0 ms

Google Tag Manager

script

326 kB

151 ms

YouTube

image

101 kB

0 ms

Google CDN

30.4 kB

6 ms

JSDelivr CDN

3.7 kB

1 ms

All 7

1.01 MB

158 ms

Page health

Metric	Value	Change / range
Main Thread Work	1.69 s	↓ -36 ms (-2.1%) 1.35 s – 1.75 s
Long Tasks	5	→ no change 4 – 5
DOM Elements	2,220	↑ +5 (+0.2%) 2,215 – 2,244
Axe Violations Violating nodes from a full Axe CLI run (more than Lighthouse reports)	1	→ no change 1 – 3
A11y Failures	1	→ no change 1 – 1
A11y Failing Nodes	1	→ no change 1 – 1

Metric

Value

Change / range

Trend

Main Thread Work

1.69 s

↓ -36 ms (-2.1%) 1.35 s – 1.75 s

Long Tasks

→ no change 4 – 5

DOM Elements

2,220

↑ +5 (+0.2%) 2,215 – 2,244

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

→ no change 1 – 3

A11y Failures

→ no change 1 – 1

A11y Failing Nodes

→ no change 1 – 1

Main thread work

Task	Share	Duration Simulated
script evaluation	53%	898 ms
other	19%	319 ms
style layout	15%	258 ms
script parse compile	8%	135 ms
parse HTML	3%	53 ms
paint composite render	2%	29 ms
Total		1.69 s

Task

Time

Duration Simulated

script evaluation

53%

898 ms

other

19%

319 ms

style layout

15%

258 ms

script parse compile

135 ms

parse HTML

53 ms

paint composite render

29 ms

Total

1.69 s

Axe violations axe-core 4.13.0, full rule set

1 violating node across 1 rule, 793 passing. This is a standalone Axe CLI run and is stricter than the subset Lighthouse already includes.

serious tabindex — Elements should not have tabindex greater than zero 1 node

Offending element

#skip-to-main

<a id="skip-to-main" class="filled-button" tabindex="1" href="#site-content-title">Skip to main content</a>

Accessibility failures 1 of 29 audits

tabindex — Some elements have a `[tabindex]` value greater than 0 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	1.38 s	155 ms	1.22 s	640 ms
2026-09-19	1.38 s	153 ms	1.21 s	632 ms
2026-09-12	1.38 s	146 ms	1.20 s	632 ms
2026-09-05	1.38 s	149 ms	1.21 s	650 ms
2026-08-29	1.37 s	144 ms	1.21 s	673 ms
2026-08-22	1.39 s	147 ms	1.23 s	709 ms
2026-08-15	1.42 s	150 ms	1.25 s	737 ms
2026-08-08	1.39 s	144 ms	1.23 s	709 ms
2026-08-01	1.39 s	145 ms	1.21 s	717 ms
2026-07-25	1.35 s	142 ms	1.19 s	678 ms
2026-07-18	1.35 s	143 ms	1.19 s	686 ms
2026-07-11	1.34 s	145 ms	1.20 s	695 ms

Week ending

LCP

INP

CLS

FCP

TTFB

2026-09-26

1.38 s

155 ms

1.22 s

640 ms

2026-09-19

1.38 s

153 ms

1.21 s

632 ms

2026-09-12

1.38 s

146 ms

1.20 s

632 ms

2026-09-05

1.38 s

149 ms

1.21 s

650 ms

2026-08-29

1.37 s

144 ms

1.21 s

673 ms

2026-08-22

1.39 s

147 ms

1.23 s

709 ms

2026-08-15

1.42 s

150 ms

1.25 s

737 ms

2026-08-08

1.39 s

144 ms

1.23 s

709 ms

2026-08-01

1.39 s

145 ms

1.21 s

717 ms

2026-07-25

1.35 s

142 ms

1.19 s

678 ms

2026-07-18

1.35 s

143 ms

1.19 s

686 ms

2026-07-11

1.34 s

145 ms

1.20 s

695 ms

Runs

Every stored run for this URL, newest first.

When	Perf	LCP	CLS	TBT	Weight	Runs	Spread	Bench	Took	Archive
Oct 3, 2026, 1:11 PM UTC	71	5.29 s	0.029	347 ms	1.20 MB	3/3	±19	2,423 -3%	26.5s	Wayback
Sep 26, 2026, 9:15 AM UTC	89	2.16 s	0.029	363 ms	1.20 MB	3/3	±1	2,479 0%	26.7s	Wayback
Sep 19, 2026, 8:41 AM UTC	89	2.13 s	0.029	378 ms	1.20 MB	3/3	±19	2,498 0%	28.1s	Wayback
Sep 12, 2026, 1:13 AM UTC	82	3.05 s	0.007	326 ms	1.19 MB	3/3	±7	2,471 -1%	27s	Wayback
Sep 4, 2026, 11:52 PM UTC	88	2.41 s	0.029	362 ms	1.19 MB	3/3	±18	2,682 +8%	25.9s	Wayback
Aug 28, 2026, 11:30 PM UTC	94	1.99 s	0.029	214 ms	1.18 MB	3/3	±37	2,987 +20%	25.8s	Wayback
Aug 20, 2026, 9:30 PM UTC	83	2.90 s	0.029	320 ms	1.18 MB	3/3	±11	2,359 -5%	26.4s	Wayback

When

Scores

Perf

LCP

CLS

TBT

Weight

Runs

Spread

Bench

Took

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Lighthouse Scores LAB 🤖 Simulated

Metrics LAB FIELD

LCP Subparts LAB 🐇 Unthrottled

LCP LAB 🤖 Simulated vs LCP FIELD

Page weight

By resource type

Third parties 7 entities

Page health

Main thread work

Axe violations axe-core 4.13.0, full rule set

Accessibility failures 1 of 29 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