reactrouter.com

Data from Aug 23, 2026, 7:32 AM UTC 14h old

Site Generators #12 · 3 measurements · since Aug 21, 2026

The measuring machine was faster than usual.

Lighthouse benchmark index was 3101 against a baseline of 2475.3 (25.3%). CPU-bound metrics — TBT, TTI, main thread work — are affected by this and may have moved without the site changing at all.

Stack

Detected on the same page load as the accessibility pass — the generator from <meta name="generator"> or the shape of the page, the host from response headers.

Fl Hosted by Fly.io

Core Web Vitals field data, url-level

Real Chrome users, 28-day window (2026-07-25 → 2026-08-21). This is what Google measures you on.

LCP 1.48 s good

INP 109 ms good

CLS 0 good

Scores

Performance

no change

Accessibility

no change

100

Best Practices

no change

SEO

no change

Filmstrip Lighthouse, mobile

How the page drew during the measured load, at 8 points across 3.00 s.

375 ms
750 ms
1.13 s
1.50 s
1.88 s
2.25 s
2.63 s
3.00 s

Lab metrics Lighthouse, mobile

Metric	Current	Previous	Change	Best	Worst
LCP Largest Contentful Paint	1.96 s	1.96 s	→ no change	1.96 s	1.96 s
CLS Cumulative Layout Shift	0	0	→ no change	0	0
TBT Total Blocking Time	0 ms	62 ms	↓ -62 ms (-100%)	0 ms	62 ms
FCP First Contentful Paint	1.81 s	1.81 s	→ no change	1.81 s	1.81 s
Speed Index	1.81 s	1.81 s	→ no change	1.81 s	1.81 s
TTFB Time to First Byte	608 ms	608 ms	→ no change	607 ms	608 ms

Metric

Current

Change

Best

Worst

Trend

LCP Largest Contentful Paint

1.96 s

→ no change

1.96 s

CLS Cumulative Layout Shift

→ no change

TBT Total Blocking Time

0 ms

62 ms

↓ -62 ms (-100%)

0 ms

62 ms

FCP First Contentful Paint

1.81 s

→ no change

1.81 s

Speed Index

1.81 s

→ no change

1.81 s

TTFB Time to First Byte

608 ms

→ no change

607 ms

608 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 1.96 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 61 ms

time to first byte 3 ms

Field data Chrome UX Report, url-level

Real Chrome users, 28-day trailing window (2026-07-25 → 2026-08-21). This is what Google measures you on.

Metric	p75	Rating	Distribution (good / needs work / poor)
LCP CWV	1.48 s	good	89% good
INP CWV Interaction to Next Paint — field only, Lighthouse cannot measure this in a lab run	109 ms	good	91.3% good
CLS CWV	0	good	97.5% good
FCP	1.50 s	good	80.5% good
TTFB	953 ms	needs-improvement	71% good

Metric

p75

Rating

Distribution (good / needs work / poor)

LCP CWV

1.48 s

good

89% good

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

109 ms

good

91.3% good

CLS CWV

good

97.5% good

FCP

1.50 s

good

80.5% good

TTFB

953 ms

needs-improvement

71% good

Lab vs field

Lab LCP 1.96 s · field p75 1.48 s · real users are 0.75× 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	1.48 s	110 ms	1.51 s	909 ms
2026-08-08	1.37 s	110 ms	1.38 s	812 ms
2026-08-01	1.30 s	111 ms	1.31 s	770 ms
2026-07-25	1.30 s	107 ms	1.31 s	770 ms
2026-07-18	1.25 s	110 ms	1.26 s	735 ms
2026-07-11	1.26 s	114 ms	1.27 s	736 ms
2026-07-04	1.29 s	117 ms	1.31 s	743 ms
2026-06-27	1.33 s	121 ms	1.34 s	742 ms
2026-06-20	1.44 s	121 ms	1.47 s	823 ms
2026-06-13	1.43 s	119 ms	1.45 s	813 ms
2026-06-06	1.42 s	120 ms	1.47 s	788 ms
2026-05-30	1.42 s	120 ms	1.45 s	783 ms

Week ending

LCP

INP

CLS

FCP

TTFB

2026-08-15

1.48 s

110 ms

1.51 s

909 ms

2026-08-08

1.37 s

110 ms

1.38 s

812 ms

2026-08-01

1.30 s

111 ms

1.31 s

770 ms

2026-07-25

1.30 s

107 ms

1.31 s

770 ms

2026-07-18

1.25 s

110 ms

1.26 s

735 ms

2026-07-11

1.26 s

114 ms

1.27 s

736 ms

2026-07-04

1.29 s

117 ms

1.31 s

743 ms

2026-06-27

1.33 s

121 ms

1.34 s

742 ms

2026-06-20

1.44 s

121 ms

1.47 s

823 ms

2026-06-13

1.43 s

119 ms

1.45 s

813 ms

2026-06-06

1.42 s

120 ms

1.47 s

788 ms

2026-05-30

1.42 s

120 ms

1.45 s

783 ms

Page weight

Metric	Current	Previous	Change	Best	Worst
Page Weight	309 kB	306 kB	↑ +2.9 kB (+1%)	306 kB	309 kB
Requests	22	22	→ no change	22	22
Third-party Weight	0 B	0 B	→ no change	0 B	0 B
Third-party CPU	0 ms	0 ms	→ no change	0 ms	0 ms
Unused JS	47.3 kB	47.3 kB	↓ -30 B (-0.1%)	47.3 kB	47.3 kB
Unused CSS	0 B	0 B	→ no change	0 B	0 B

Metric

Current

Change

Best

Worst

Trend

Page Weight

309 kB

306 kB

↑ +2.9 kB (+1%)

306 kB

309 kB

Requests

→ no change

Third-party Weight

0 B

→ no change

0 B

Third-party CPU

0 ms

→ no change

0 ms

Unused JS

47.3 kB

↓ -30 B (-0.1%)

47.3 kB

Unused CSS

0 B

→ no change

0 B

By resource type

script 137 kB · 9 req

image 98.8 kB · 6 req

font 52.9 kB · 1 req

stylesheet 11.0 kB · 2 req

document 5.4 kB · 1 req

other 4.6 kB · 3 req

Page health

Metric	Current	Previous	Change	Best	Worst
Main Thread Work	420 ms	1.19 s	↓ -769 ms (-64.7%)	420 ms	1.19 s
Long Tasks	0	5	↓ -5 (-100%)	0	5
DOM Elements	108	108	→ no change	108	108
Axe Violations Violating nodes from a full axe run — stricter than Lighthouse's subset	9	9	→ no change	9	9
A11y Failures	2	2	→ no change	2	2
A11y Failing Nodes	9	9	→ no change	9	9

Main thread work

other 173 ms

script evaluation 144 ms

style layout 57 ms

parse HTML 27 ms

paint composite render 12 ms

script parse compile 8 ms

Axe violations axe-core 4.13.0, full rule set

9 violating nodes across 2 rules, 165 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.

serious dlitem — <dt> and <dd> elements must be contained by a <dl> 8 nodes
serious definition-list — <dl> elements must only directly contain properly-ordered <dt> and <dd> groups, <script>, <template> or <div> elements 1 node

Accessibility failures 2 of 14 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.

dlitem — Definition list items are not wrapped in `<dl>` elements 8 nodes
definition-list — `<dl>`'s do not contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements. 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	TBT	Weight	Runs	Spread	Bench	Took
Aug 23, 2026, 7:32 AM UTC	98	1.96 s	0 ms	309 kB	3/3	±1	3,101	19.9s
Aug 22, 2026, 7:31 AM UTC	98	1.96 s	62 ms	306 kB	3/3	±0	2,484	21.5s
Aug 21, 2026, 6:52 AM UTC	98	1.96 s	0 ms	309 kB	3/3	±0	2,467	21s

When

Perf

LCP

CLS

TBT

Weight

Runs

Spread

Bench

Took

Aug 23, 2026, 7:32 AM UTC

1.96 s

0 ms

309 kB

3/3

±1

3,101

19.9s

Aug 22, 2026, 7:31 AM UTC

1.96 s

62 ms

306 kB

3/3

±0

2,484

21.5s

Aug 21, 2026, 6:52 AM UTC

1.96 s

0 ms

309 kB

3/3

±0

2,467

21s

Embed this score

Live below, then the markup that produces it. Drop that on any page to show reactrouter.com'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://reactrouter.com/"></speedlify2-score>