docs.flutter.dev

https://docs.flutter.dev/

Data from Aug 20, 2026, 9:30 PM UTC 3d old

Built Awesome #700 · 1 measurement · since Aug 20, 2026

Core Web Vitals field data, url-level

Real Chrome users, 28-day window (2026-07-22 → 2026-08-18). This is what Google measures you on.

LCP 1.39 s good

INP 147 ms good

CLS 0 good

Scores

Performance

no change

Accessibility

no change

100

Best Practices

no change

SEO

no change

Lab metrics Lighthouse, mobile

Metric	Current	Previous	Change	Best	Worst
LCP Largest Contentful Paint	2.90 s	—	—	2.90 s	2.90 s
CLS Cumulative Layout Shift	0.029	—	—	0.029	0.029
TBT Total Blocking Time	320 ms	—	—	320 ms	320 ms
FCP First Contentful Paint	2.90 s	—	—	2.90 s	2.90 s
Speed Index	2.90 s	—	—	2.90 s	2.90 s
TTFB Time to First Byte	614 ms	—	—	614 ms	614 ms

What LCP is made of observed, unthrottled

A flat LCP number tells you something regressed. The subparts tell you whether it was the server, resource discovery, the download, or rendering.

Measured on the trace before throttling is modelled, so these are real durations that will not sum to the 2.90 s above — that figure is a simulation of the same load on a slow phone and connection. Read these for the proportions: which phase dominates.

element render delay 118 ms

time to first byte 10 ms

Field data Chrome UX Report, url-level

Real Chrome users, 28-day trailing window (2026-07-22 → 2026-08-18). This is what Google measures you on.

Metric	p75	Rating	Distribution (good / needs work / poor)
LCP CWV	1.39 s	good	89.3% good
INP CWV Interaction to Next Paint — field only, Lighthouse cannot measure this in a lab run	147 ms	good	84.8% good
CLS CWV	0	good	97.8% good
FCP	1.24 s	good	84.7% good
TTFB	718 ms	good	78.4% good

Metric

p75

Rating

Distribution (good / needs work / poor)

LCP CWV

1.39 s

good

89.3% good

INP CWV Interaction to Next Paint — field only, Lighthouse cannot measure this in a lab run

147 ms

good

84.8% good

CLS CWV

good

97.8% good

FCP

1.24 s

good

84.7% good

TTFB

718 ms

good

78.4% good

Lab vs field

Lab LCP 2.90 s · field p75 1.39 s · real users are 0.48× faster than the lab.

Field history 25 weeks

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

Week ending	LCP	INP	FCP	TTFB
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
2026-07-04	1.34 s	141 ms	1.22 s	693 ms
2026-06-27	1.36 s	144 ms	1.23 s	731 ms
2026-06-20	1.34 s	145 ms	1.22 s	719 ms
2026-06-13	1.33 s	147 ms	1.19 s	708 ms
2026-06-06	1.33 s	154 ms	1.19 s	678 ms
2026-05-30	1.33 s	156 ms	1.19 s	664 ms

Week ending

LCP

INP

CLS

FCP

TTFB

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

2026-07-04

1.34 s

141 ms

1.22 s

693 ms

2026-06-27

1.36 s

144 ms

1.23 s

731 ms

2026-06-20

1.34 s

145 ms

1.22 s

719 ms

2026-06-13

1.33 s

147 ms

1.19 s

708 ms

2026-06-06

1.33 s

154 ms

1.19 s

678 ms

2026-05-30

1.33 s

156 ms

1.19 s

664 ms

Page weight

Metric	Current	Previous	Change	Best	Worst
Page Weight	1.18 MB	—	—	1.18 MB	1.18 MB
Requests	75	—	—	75	75
Third-party Weight	988 kB	—	—	988 kB	988 kB
Third-party CPU	151 ms	—	—	151 ms	151 ms
Unused JS	149 kB	—	—	149 kB	149 kB
Unused CSS	0 B	—	—	0 B	0 B

By resource type

font 543 kB · 2 req

script 456 kB · 44 req

image 105 kB · 11 req

other 39.3 kB · 13 req

document 17.3 kB · 1 req

stylesheet 16.2 kB · 3 req

third party 988 kB · 20 req

Third parties 6 entities

988 kB transferred, 151 ms of main thread time. This is the number most likely to regress without anyone on your team shipping anything.

Google Fonts 546 kB · 0 ms CPU

Google Tag Manager 317 kB · 138 ms CPU

YouTube 101 kB · 0 ms CPU

Google Analytics 21.0 kB · 12 ms CPU

JSDelivr CDN 3.7 kB · 1 ms CPU

Page health

Metric	Current	Previous	Change	Best	Worst
Main Thread Work	1.68 s	—	—	1.68 s	1.68 s
Long Tasks	5	—	—	5	5
DOM Elements	2,244	—	—	2,244	2,244
Axe Violations Violating nodes from a full axe run — stricter than Lighthouse's subset	3	—	—	3	3
A11y Failures	1	—	—	1	1
A11y Failing Nodes	1	—	—	1	1

Main thread work

script evaluation 893 ms

other 341 ms

style layout 238 ms

script parse compile 143 ms

parse HTML 40 ms

paint composite render 23 ms

Axe violations axe-core 4.13.0, full rule set

3 violating nodes across 2 rules, 809 passing. This is a standalone axe run, stricter than the subset Lighthouse folds into its score above — and it is the second tiebreaker in the ranking.

moderate region — All page content should be contained by landmarks 2 nodes
serious tabindex — Elements should not have tabindex greater than zero 1 node

Accessibility failures 1 of 29 audits

Tracked as a count, not just the score — the weighted score is coarse enough that you can ship a broken component and barely move it.

tabindex — Some elements have a `[tabindex]` value greater than 0 1 node

Hygiene

Changes rarely — which is exactly why a change is worth noticing.

HTTPS HSTS CSP Clickjacking protection Origin isolation Trusted Types bfcache h2

Measurement log

Every stored run for this URL, newest first. Failures are kept as records — "this site was down on Tuesday" is data too.

When	Perf	LCP	CLS	TBT	Weight	Runs	Spread	Bench	Took
Aug 20, 2026, 9:30 PM UTC	83	2.90 s	0.029	320 ms	1.18 MB	3/3	±11	2,359	26.4s

When

Perf

LCP

CLS

TBT

Weight

Runs

Spread

Bench

Took

Aug 20, 2026, 9:30 PM UTC

2.90 s

0.029

320 ms

1.18 MB

3/3

±11

2,359

26.4s

Embed this score

Live below, then the markup that produces it. Drop that on any page to show docs.flutter.dev's scores, updated whenever this instance re-measures — more about the component. Don’t forget to bundle the speedlify2-score.js component code into your site!

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