https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2023/07/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/themes/maintheme... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2026/04/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2023/07/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.zimbra.com/wp-content/uploads/2025/09/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
77images1.9 MB
0oversized-0 KB
77legacy format
24missing 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
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
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
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
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
2 fonts (60 KB)
PASS
2 fonts (60 KB)
Info::
i
2 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
2
60 KB total
Render-blocking
0
of 2
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
UcC73FwrK3iLTeHuS_nVMrM...woff2swap
Size47 KB
Load time24 ms
Start268 ms
RiskFOUT — text flashes from fallback to web font
latin.woff2woff2swap
Size13 KB
Load time6 ms
Start1.5 s
RiskFOUT — 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)
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
A
HTTP Caching
max-age=86400 (1 day)
PASS
max-age=86400 (1 day)
Info::
✓
Cache-Control header is set
Got: public, max-age=86400
Info::
✓
Effective TTL: 1 day (max-age=86400)
Info::
i
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control
public, max-age=86400
Directive
Value
Meaning
public
—
Any cache may store this response
max-age
86400
Cache for 1 day
Effective TTL: 86400 seconds
Network Waterfall
145 requests over 3661ms
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-party3704ms · 795KB · €59/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.zimbra.com
www.zimbra.com
Other
2105ms
59 KB
—
€34/mo
Costly
www.zimbra.com
www.zimbra.com
Other
576ms
35 KB
—
€9/mo
Costly
Unattributable
Unattributable
Other
324ms
0 KB
—
€5/mo
Costly
HubSpot Analytics
js.hs-analytics.net
Analytics
185ms
43 KB
—
€3/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
113ms
173 KB
37%
€2/mo
Optional
consent.trustarc.com
consent.trustarc.com
Other
109ms
32 KB
—
€2/mo
Optional
acsbapp.com
acsbapp.com
Other
99ms
222 KB
58%
€2/mo
Optional
js.hsforms.net
js.hsforms.net
Other
97ms
194 KB
40%
€2/mo
Optional
www.zimbra.com
www.zimbra.com
Other
94ms
38 KB
61%
€2/mo
Optional
www.zimbra.com
Other
Costly
Execution2105ms
Transfer59 KB
Monthly Cost€34/mo
www.zimbra.com
Other
Costly
Execution576ms
Transfer35 KB
Monthly Cost€9/mo
Unattributable
Other
Costly
Execution324ms
Transfer0 KB
Monthly Cost€5/mo
HubSpot Analytics
Analytics
Optional
Execution185ms
Transfer43 KB
Monthly Cost€3/mo
Google Tag Manager
Tag Manager
Optional
Execution113ms
Transfer173 KB
Unused37%
Monthly Cost€2/mo
consent.trustarc.com
Other
Optional
Execution109ms
Transfer32 KB
Monthly Cost€2/mo
acsbapp.com
Other
Optional
Execution99ms
Transfer222 KB
Unused58%
Monthly Cost€2/mo
js.hsforms.net
Other
Optional
Execution97ms
Transfer194 KB
Unused40%
Monthly Cost€2/mo
www.zimbra.com
Other
Optional
Execution94ms
Transfer38 KB
Unused61%
Monthly Cost€2/mo
These scripts may cost more than they're worth
www.zimbra.com adds 2105ms and costs ~€34/month
www.zimbra.com adds 576ms and costs ~€9/month
Unattributable adds 324ms and costs ~€5/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.zimbra.com 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
www.zimbra.com takes 576ms 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 324ms 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 acsbapp.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
61% of www.zimbra.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.