Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
B
Image Optimization
22 images, 0 KB saveable
REVIEW
22 images, 0 KB saveable
Warning::
!
https://www.weforum.org/a-weekly-logo.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
22images1.5 MB
0oversized-0 KB
13legacy format
1missing dimensionsCLS 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
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW
Green Hosting
No green hosting detected
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
3 fonts (378 KB)
PASS
3 fonts (378 KB)
Info::
i
3 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
3
378 KB total
Render-blocking
0
of 3
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
AkkuratLLWeb-Regular.woff2woff2swap
Size108 KB
Load time49 ms
Start703 ms
RiskFOUT — 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
AkkuratLLWeb-Black.woff2woff2swap
Size112 KB
Load time42 ms
Start899 ms
RiskFOUT — 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
AkkuratLLWeb-Bold.woffwoffswap
Size158 KB
Load time53 ms
Start899 ms
RiskFOUT — text flashes from fallback to web font
Convert to woff2 for ~30% smaller file size
Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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 ~236 KB and ~472 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
6 hints, 0 missing preconnects
PASS
6 hints, 0 missing preconnects
Info::
✓
Page uses 6 resource hint(s)
Current Resource Hints
preconnect
5
preload—
dns-prefetch
1
prefetch—
6 resource hints configured
A+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
✓
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
Network Waterfall
95 requests over 6053ms
INFO
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
100%of JavaScript execution is third-party
First-party Third-party14763ms · 3136KB · €160/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.weforum.org
www.weforum.org
Other
2450ms
55 KB
—
€27/mo
Costly
www.weforum.org
www.weforum.org
Other
2105ms
108 KB
—
€23/mo
Costly
consent.cookiebot.com
consent.cookiebot.com
Other
1124ms
121 KB
21%
€12/mo
Costly
mfe.weforum.org
mfe.weforum.org
Other
1120ms
384 KB
30%
€12/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
868ms
175 KB
36%
€9/mo
Costly
www.weforum.org
www.weforum.org
Other
854ms
438 KB
46%
€9/mo
Costly
dev.visualwebsiteoptimizer.com
dev.visualwebsiteoptimizer.com
Other
843ms
97 KB
64%
€9/mo
Costly
mfe.weforum.org
mfe.weforum.org
Other
746ms
1 KB
—
€8/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
742ms
173 KB
42%
€8/mo
Costly
Unattributable
Unattributable
Other
736ms
0 KB
—
€8/mo
Costly
www.weforum.org
www.weforum.org
Other
700ms
225 KB
58%
€8/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
534ms
176 KB
37%
€6/mo
Costly
www.weforum.org
www.weforum.org
Other
364ms
28 KB
91%
€4/mo
Costly
consent.cookiebot.com
consent.cookiebot.com
Other
271ms
36 KB
—
€3/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
265ms
172 KB
40%
€3/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
210ms
146 KB
44%
€2/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
191ms
141 KB
45%
€2/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
158ms
129 KB
48%
€2/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
87ms
176 KB
65%
€1/mo
Optional
auth-widgets.weforum.org
auth-widgets.weforum.org
Other
85ms
84 KB
57%
€1/mo
Optional
www.weforum.org
www.weforum.org
Other
71ms
110 KB
—
€1/mo
Optional
dev.visualwebsiteoptimizer.com
dev.visualwebsiteoptimizer.com
Other
71ms
15 KB
—
€1/mo
Optional
dev.visualwebsiteoptimizer.com
dev.visualwebsiteoptimizer.com
Other
60ms
44 KB
83%
€1/mo
Optional
dev.visualwebsiteoptimizer.com
dev.visualwebsiteoptimizer.com
Other
60ms
26 KB
—
€1/mo
Optional
www.weforum.org
www.weforum.org
Other
51ms
77 KB
65%
€1/mo
Optional
www.weforum.org
Other
Costly
Execution2450ms
Transfer55 KB
Monthly Cost€27/mo
www.weforum.org
Other
Costly
Execution2105ms
Transfer108 KB
Monthly Cost€23/mo
consent.cookiebot.com
Other
Costly
Execution1124ms
Transfer121 KB
Unused21%
Monthly Cost€12/mo
mfe.weforum.org
Other
Costly
Execution1120ms
Transfer384 KB
Unused30%
Monthly Cost€12/mo
Google Tag Manager
Tag Manager
Costly
Execution868ms
Transfer175 KB
Unused36%
Monthly Cost€9/mo
www.weforum.org
Other
Costly
Execution854ms
Transfer438 KB
Unused46%
Monthly Cost€9/mo
dev.visualwebsiteoptimizer.com
Other
Costly
Execution843ms
Transfer97 KB
Unused64%
Monthly Cost€9/mo
mfe.weforum.org
Other
Costly
Execution746ms
Transfer1 KB
Monthly Cost€8/mo
Google Tag Manager
Tag Manager
Costly
Execution742ms
Transfer173 KB
Unused42%
Monthly Cost€8/mo
Unattributable
Other
Costly
Execution736ms
Transfer0 KB
Monthly Cost€8/mo
www.weforum.org
Other
Costly
Execution700ms
Transfer225 KB
Unused58%
Monthly Cost€8/mo
Google Tag Manager
Tag Manager
Costly
Execution534ms
Transfer176 KB
Unused37%
Monthly Cost€6/mo
www.weforum.org
Other
Costly
Execution364ms
Transfer28 KB
Unused91%
Monthly Cost€4/mo
consent.cookiebot.com
Other
Costly
Execution271ms
Transfer36 KB
Monthly Cost€3/mo
Google Tag Manager
Tag Manager
Costly
Execution265ms
Transfer172 KB
Unused40%
Monthly Cost€3/mo
Google Tag Manager
Tag Manager
Costly
Execution210ms
Transfer146 KB
Unused44%
Monthly Cost€2/mo
Google Tag Manager
Tag Manager
Optional
Execution191ms
Transfer141 KB
Unused45%
Monthly Cost€2/mo
Google Tag Manager
Tag Manager
Optional
Execution158ms
Transfer129 KB
Unused48%
Monthly Cost€2/mo
Google Tag Manager
Tag Manager
Optional
Execution87ms
Transfer176 KB
Unused65%
Monthly Cost€1/mo
auth-widgets.weforum.org
Other
Optional
Execution85ms
Transfer84 KB
Unused57%
Monthly Cost€1/mo
www.weforum.org
Other
Optional
Execution71ms
Transfer110 KB
Monthly Cost€1/mo
dev.visualwebsiteoptimizer.com
Other
Optional
Execution71ms
Transfer15 KB
Monthly Cost€1/mo
dev.visualwebsiteoptimizer.com
Other
Optional
Execution60ms
Transfer44 KB
Unused83%
Monthly Cost€1/mo
dev.visualwebsiteoptimizer.com
Other
Optional
Execution60ms
Transfer26 KB
Monthly Cost€1/mo
www.weforum.org
Other
Optional
Execution51ms
Transfer77 KB
Unused65%
Monthly Cost€1/mo
These scripts may cost more than they're worth
www.weforum.org adds 2450ms and costs ~€27/month
www.weforum.org adds 2105ms and costs ~€23/month
consent.cookiebot.com adds 1124ms and costs ~€12/month
mfe.weforum.org adds 1120ms and costs ~€12/month
Google Tag Manager adds 868ms and costs ~€9/month
www.weforum.org adds 854ms and costs ~€9/month
dev.visualwebsiteoptimizer.com adds 843ms and costs ~€9/month
mfe.weforum.org adds 746ms and costs ~€8/month
Google Tag Manager adds 742ms and costs ~€8/month
Unattributable adds 736ms and costs ~€8/month
www.weforum.org adds 700ms and costs ~€8/month
Google Tag Manager adds 534ms and costs ~€6/month
www.weforum.org adds 364ms and costs ~€4/month
consent.cookiebot.com adds 271ms and costs ~€3/month
Google Tag Manager adds 265ms and costs ~€3/month
Google Tag Manager adds 210ms and costs ~€2/month
100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.
Why this matters
When third-party JS execution time exceeds your own, performance gains from frontend work are capped by code you don't own.
Learn more ▾▴
Every millisecond of third-party JS competes with your own for main-thread time. If their share is bigger than yours, optimization on your code base barely moves the needle. Audit, defer, or remove third-parties before further frontend optimization. Use Lighthouse's third-party audit to identify the worst offenders.
Source: web.dev
www.weforum.org takes 2450ms 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
www.weforum.org takes 2105ms 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
consent.cookiebot.com takes 1124ms 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
mfe.weforum.org takes 1120ms 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
Google Tag Manager takes 868ms 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
www.weforum.org takes 854ms 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
dev.visualwebsiteoptimizer.com takes 843ms 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
64% of dev.visualwebsiteoptimizer.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
mfe.weforum.org takes 746ms 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
Google Tag Manager takes 742ms 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
Unattributable takes 736ms 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
www.weforum.org takes 700ms 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
58% of www.weforum.org'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
Google Tag Manager takes 534ms 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
www.weforum.org takes 364ms 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
91% of www.weforum.org'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
consent.cookiebot.com takes 271ms 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
Google Tag Manager takes 265ms 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
Google Tag Manager takes 210ms 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
65% of Google Tag Manager'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
57% of auth-widgets.weforum.org'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
83% of dev.visualwebsiteoptimizer.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
65% of www.weforum.org'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.