Performance

· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop

Performance

Accessibility

Best Practices

SEO

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

783 ms

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

2.12 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

0 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.090

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

783 ms

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

2.12 s

Page Load Progression

375 ms

750 ms

1.1 s

1.5 s

1.9 s

2.2 s

2.6 s

3.0 s

Checks

10 PASS 2 REVIEW 1 FIX

Page Weight Budget

Action

2.4 MB transferred, 143 requests

FIX

2.4 MB transferred, 143 requests

Page weighs 4.6 MB (2.4 MB transferred)

Images are 1.9 MB — compress or use modern formats

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Got: 1.9 MB

CSS is 200 KB — consider purging unused styles

Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.

Got: 200 KB

143 HTTP requests — consider bundling or reducing

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Estimated 0.49 g CO2 per page load

2.4 MB transferred

143 requests

0.49 g CO2 per page load

Images 1.9 MiB 81%

CSS 200.4 KiB 8%

HTML 130.3 KiB 5%

Fonts 119.4 KiB 5%

Other 1.3 KiB 0%

Other 725 B 0%

JavaScript 0 B 0%

0 2.4 MB 4.9 MB

Approaching limit

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Why this matters

Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.

Source: web.dev

Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.

Why this matters

CSS bundle is large — purge unused styles (PurgeCSS, Tailwind JIT) to reduce CSS payload.

Source: web.dev

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Why this matters

High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.

Source: web.dev

Image Optimization

Action

53 images, 0 KB saveable

REVIEW

53 images, 0 KB saveable

https://ktla.com/wp-content/themes/nexstar/client/... is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

https://cdn.bestreviews.com/images/logo_new.svg?w=... is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

53 images 1.9 MB

0 oversized -0 KB

7 legacy format

3 missing dimensions CLS risk

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Page Weight Inventory

Action

143 resources · 2.4 MB · 0 KB savings available

REVIEW

143 resources · 2.4 MB · 0 KB savings available

Page weight 1.4 MB over 1MB target

Got: 2.4 MB Expected: ≤ 1 MB

38 third-party resources (31% of weight)

3 resources over 200KB

143 resources · 2.4 MiB · 38 third-party 1.4 MiB over 1MB target

Image 81% · 1.9 MiB

CSS 8% · 200.4 KiB

Document 5% · 130.3 KiB

Font 5% · 119.4 KiB

Other 0% · 725 B

JavaScript 0% · 0 B

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

143 resources			2.4 MiB

Third-Party Impact

31% third-party, 0 ms blocking

PASS

31% third-party, 0 ms blocking

Third-party code accounts for 31% of page weight (759.0 KiB of 2.4 MiB)

Third-party blocking time is low (0 ms)

69%

31%

First-party Third-party

A+

Text Compression

All text resources are compressed

PASS

All text resources are compressed

All text resources are properly compressed.

A+

JS Execution Cost

402ms total JS execution

PASS

402ms total JS execution

https://ktla.com/: 292ms CPU time

Unattributable: 110ms CPU time

Third-party scripts: 110ms (27% of total)

Main Thread Breakdown

Style & Layout 41% Other 31% Parse HTML & CSS 15% Rendering 9% Script Evaluation 3%

Script	Total	Scripting	Parse/Compile	Party
https://ktla.com/	292ms	11ms	0ms	1st
Unattributable	110ms	2ms	0ms	3rd

A+

Font Loading

7 fonts (119 KB)

PASS

7 fonts (119 KB)

7 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

119 KB total

Render-blocking

of 7

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

6xK3dSBYKcSV-LCoeQqfX1R... woff2 swap

Size 15 KB

Load time 30 ms

Start 263 ms