Skip to content
https://www.redcross.org

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
71
GRADE
C
FIX
2
REVIEW
4
PASS
6
INFO
2

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

Mobile Desktop
65
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
92
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
73
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
92
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

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

1.24 s

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

2.09 s

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

100 ms

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

0.439

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

1.38 s

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

6.23 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
14
6 PASS 4 REVIEW 2 FIX
F
Page Weight Budget
Action
4.7 MB transferred, 231 requests
FIX
4.7 MB transferred, 231 requests
Critical::
Page weighs 10.5 MB (4.7 MB transferred)
Warning::
Images are 2.3 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 2.3 MB
Warning::
JavaScript is 1.8 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.8 MB
Info::
Fonts are 376 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 376 KB
Warning::
231 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 0.99 g CO2 per page load
4.7 MB / 2.4 MB budget
4.7 MB transferred
231 requests
0.99 g CO2 per page load
Images 2.3 MiB 48%
JavaScript 1.8 MiB 39%
Fonts 376.5 KiB 8%
CSS 124.7 KiB 3%
Other 85.5 KiB 2%
HTML 27.9 KiB 1%
Other 12.0 KiB 0%
Other 8.8 KiB 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over budget

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

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Why this matters

JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.

Source: web.dev

Subset fonts to include only used characters, or switch to system font stacks.

Why this matters

Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).

Source: web.dev font loading

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

F
JS Bundles
Action
96 scripts, 773 KB unused
FIX
96 scripts, 773 KB unused
Warning::
https://www.redcross.org/etc/clientlibs/redcross/s...: 157 KB unused (72%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.redcross.org/etc/clientlibs/redcross/s...: unminified — 35 KB could be saved
Warning::
https://maps.googleapis.com/maps/api/js?key=AIzaSy...: 146 KB unused (58%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://doublethedonation.com/api/js/ddplugin.js: 81 KB unused (66%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cdn.cookielaw.org/scripttemplates/202507.1...: 64 KB unused (54%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://assets.adobedtm.com/16a36399704a/2efca5d8f...: 63 KB unused (29%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 773 KB
773 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.redcross.org/etc/clientlibs/redcross/shared/components.min.js219 KB157 KB (72%)✗1st
https://maps.googleapis.com/maps/api/js?key=AIzaSyBhCHZNKMH6qZxSNJbouh31lKwqcvQU0ks&callback=initMap&libraries=geometry,marker253 KB146 KB (58%)✓3rd
https://doublethedonation.com/api/js/ddplugin.js123 KB81 KB (66%)✓3rd
https://cdn.cookielaw.org/scripttemplates/202507.1.0/otBannerSdk.js120 KB64 KB (54%)✓3rd
https://assets.adobedtm.com/16a36399704a/2efca5d8f658/launch-b67461f3859d.min.js216 KB63 KB (29%)✓3rd
https://clarachat.redcross.org/main-VDEKQFFY.js117 KB54 KB (47%)✓3rd
https://www.googletagmanager.com/gtag/js?id=AW-999092293&cx=c&gtm=4e6460137 KB54 KB (40%)✓3rd
https://www.googletagmanager.com/gtag/js?id=DC-4706068129 KB53 KB (42%)✓3rd
https://s.go-mpulse.net/boomerang/G5EYL-3FTNM-K2QN3-FX5YQ-53AZH58 KB38 KB (66%)✓3rd
https://connect.facebook.net/en_US/fbevents.js95 KB37 KB (39%)✓3rd

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

C
Image Optimization
Action
54 images, 0 KB saveable
REVIEW
54 images, 0 KB saveable
Warning::
https://www.redcross.org/content/dam/icons/biomed/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.redcross.org/content/dam/icons/biomed/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.redcross.org/content/dam/icons/digital... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.redcross.org/content/dam/redcross/red-... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.redcross.org/content/dam/icons/general... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.redcross.org/content/dam/icons/general... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.redcross.org/content/dam/icons/general... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.redcross.org/content/dam/icons/general... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.redcross.org/content/dam/icons/disaste... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.redcross.org/content/dam/icons/disaste... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
54 images 2.3 MB
0 oversized -0 KB
54 legacy format
10 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

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

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

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

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

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

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

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

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

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

Source: web.dev / Core Web Vitals

C
JS Execution Cost
Action
1663ms total JS execution
REVIEW
1663ms total JS execution
Warning::
Unattributable: 394ms CPU time
Warning::
https://www.redcross.org/: 281ms CPU time
Info::
https://assets.adobedtm.com/16a36399704a/2efca5d8f...: 248ms CPU time
Info::
https://www.redcross.org/etc/clientlibs/redcross/s...: 178ms CPU time
Info::
https://clarachat.redcross.org/polyfills-5CFQRCPP....: 117ms CPU time
Warning::
Third-party scripts: 1114ms (67% of total)

Main Thread Breakdown

Script Evaluation 53% Other 17% Style & Layout 13% Script Parsing & Compilation 10% Parse HTML & CSS 3%
ScriptTotalScriptingParse/CompileParty
Unattributable394ms115ms0ms3rd
https://www.redcross.org/281ms36ms2ms1st
https://assets.adobedtm.com/16a36399704a/2efca5d8f658/launch-b67461f3859d.min.js248ms181ms37ms3rd
https://www.redcross.org/etc/clientlibs/redcross/shared/dependencies.min.js178ms107ms5ms1st
https://clarachat.redcross.org/polyfills-5CFQRCPP.js117ms97ms0ms3rd
https://cdn.cookielaw.org/scripttemplates/202507.1.0/otBannerSdk.js117ms66ms21ms3rd
https://www.redcross.org/etc/clientlibs/redcross/shared/components.min.js91ms45ms35ms1st
https://www.googletagmanager.com/gtag/js?id=DC-470606883ms67ms12ms3rd
https://www.googletagmanager.com/gtag/js?id=AW-999092293&cx=c&gtm=4e646080ms66ms13ms3rd
https://maps.googleapis.com/maps/api/js?key=AIzaSyBhCHZNKMH6qZxSNJbouh31lKwqcvQU0ks&callback=initMap&libraries=geometry,marker75ms50ms25ms3rd
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

B
HTTP Caching
max-age=0
REVIEW
max-age=0
Info::
Cache-Control header is set
Got: max-age=0
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

max-age=0

DirectiveValueMeaning
max-age0Cache for 0 seconds
A
Third-Party Impact
39% third-party, 0 ms blocking
PASS
39% third-party, 0 ms blocking
Info::
Third-party code accounts for 39% of page weight (1.9 MiB of 4.7 MiB)
Info::
Third-party blocking time is low (0 ms)
61%
39%
First-party Third-party
A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+
Font Loading
6 fonts (376 KB)
PASS
6 fonts (376 KB)
Info::
6 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

6

376 KB total

Render-blocking

0

of 6

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s 1.5 s 2.0 s FCP 1.2 s LCP 2.1 shttps://www.redcross.org/etc/clientlibs/redcross/vendor/font-awesome-6/webfonts/fa-brands-400.woff2fa-brands-400.woff2 https://www.redcross.org/etc/clientlibs/redcross/vendor/font-awesome-6/webfonts/fa-brands-400.woff2 — 115.9 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2KFO7CnqEu92Fr1ME7kSn66a... https://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2 — 36.7 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2memvYaGs126MiZpBA-UvWbX... https://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2 — 42.0 KiB — 0 ms — font-display: swaphttps://www.redcross.org/etc/clientlibs/redcross/vendor/font-awesome-6/webfonts/fa-solid-900.woff2fa-solid-900.woff2 https://www.redcross.org/etc/clientlibs/redcross/vendor/font-awesome-6/webfonts/fa-solid-900.woff2 — 154.6 KiB — 0 ms — font-display: swaphttps://www.redcross.org/etc/clientlibs/redcross/vendor/rco-icons/fonts/rco-icon.ttfrco-icon.ttf https://www.redcross.org/etc/clientlibs/redcross/vendor/rco-icons/fonts/rco-icon.ttf — 9.6 KiB — 0 ms — font-display: swaphttps://www.redcross.org/etc/clientlibs/redcross/vendor/rco-icons/fonts/glyphicons-halflings-regular.woff2glyphicons-halflings-re... https://www.redcross.org/etc/clientlibs/redcross/vendor/rco-icons/fonts/glyphicons-halflings-regular.woff2 — 17.7 KiB — 0 ms — font-display: swap
fa-brands-400.woff2 woff2 swap
Size 116 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
KFO7CnqEu92Fr1ME7kSn66a... woff2 swap
Size 37 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
memvYaGs126MiZpBA-UvWbX... woff2 swap
Size 42 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
fa-solid-900.woff2 woff2 swap
Size 155 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
rco-icon.ttf ttf swap
Size 10 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
glyphicons-halflings-re... woff2 swap
Size 18 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Optimization checklist
  • Preload critical fonts (priority=high)
  • Use woff2 format for all fonts
  • Set font-display to swap, optional, or fallback
  • Subset large fonts (≤100 KB each)

Fixing the unchecked items could save ~138 KB and ~276 ms

A+
Resource Caching
All resources properly cached
PASS
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
No render-blocking resources detected
A+
Resource Hints
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
Network Waterfall
231 requests over 0ms
INFO

Performance analysis not available for this result.

Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
67% of JavaScript execution is third-party
First-party Third-party 1114ms · 868KB · $15/mo
Unattributable
Other
Costly
Execution 394ms
Transfer 0 KB
Monthly Cost $5/mo
assets.adobedtm.com
Other
Costly
Execution 248ms
Transfer 216 KB
Unused 29%
Monthly Cost $3/mo
clarachat.redcross.org
Other
Optional
Execution 117ms
Transfer 12 KB
Monthly Cost $2/mo
OneTrust
Consent
Essential
Execution 117ms
Transfer 120 KB
Unused 54%
Monthly Cost $2/mo
Google Tag Manager
Tag Manager
Optional
Execution 83ms
Transfer 129 KB
Unused 42%
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 80ms
Transfer 137 KB
Unused 40%
Monthly Cost $1/mo
maps.googleapis.com
Other
Optional
Execution 75ms
Transfer 253 KB
Unused 58%
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • Unattributable adds 394ms and costs ~$5/month
  • assets.adobedtm.com adds 248ms and costs ~$3/month

67% of JavaScript execution time comes from third-party scripts.

Why this matters

Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.

Learn more ▾

Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.

Source: web.dev / HTTP Archive Web Almanac

Unattributable takes 394ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

assets.adobedtm.com takes 248ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

54% of OneTrust's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

58% of maps.googleapis.com's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

How third-party costs are calculated

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

Send Feedback