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.
C
Image Optimization
Action
56 images, 0 KB saveable
REVIEW
56 images, 0 KB saveable
Warning::
!
is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2026... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/rxt_... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.rackspace.com/sites/default/files/2025... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
56images804 KB
0oversized-0 KB
51legacy format
30missing dimensionsCLS risk
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
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
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
9 fonts (298 KB)
PASS
9 fonts (298 KB)
Info::
i
9 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
9
298 KB total
Render-blocking
0
of 9
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size34 KB
Load time37 ms
Start581 ms
RiskFOUT — text flashes from fallback to web font
open-sans-v18-latin-reg...woff2swap
Size14 KB
Load time47 ms
Start678 ms
RiskFOUT — text flashes from fallback to web font
open-sans-v18-latin-700...woff2swap
Size15 KB
Load time48 ms
Start682 ms
RiskFOUT — text flashes from fallback to web font
open-sans-v18-latin-600...woff2swap
Size15 KB
Load time60 ms
Start682 ms
RiskFOUT — text flashes from fallback to web font
slick.woffwoffswap
Size2 KB
Load time50 ms
Start683 ms
RiskFOUT — text flashes from fallback to web font
Convert to woff2 for ~30% smaller file size
rswebfonts.woff2woff2swap
Size62 KB
Load time54 ms
Start683 ms
RiskFOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size39 KB
Load time12 ms
Start1.8 s
RiskFOUT — text flashes from fallback to web font
memvYaGs126MiZpBA-UvWbX...woff2swap
Size42 KB
Load time15 ms
Start2.4 s
RiskFOUT — text flashes from fallback to web font
regular.woff2woff2swap
Size76 KB
Load time51 ms
Start2.9 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
Network Waterfall
178 requests over 5971ms
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-party3101ms · 1182KB · €34/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.rackspace.com
www.rackspace.com
Other
862ms
26 KB
—
€9/mo
Costly
Unattributable
Unattributable
Other
467ms
0 KB
—
€5/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
356ms
193 KB
33%
€4/mo
Costly
HubSpot Analytics
js.hs-analytics.net
Analytics
327ms
42 KB
—
€4/mo
Costly
www.rackspace.com
www.rackspace.com
Other
305ms
1 KB
22%
€3/mo
Costly
www.rackspace.com
www.rackspace.com
Other
191ms
112 KB
58%
€2/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
156ms
169 KB
40%
€2/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
152ms
175 KB
40%
€2/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
104ms
143 KB
38%
€1/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
67ms
134 KB
45%
€1/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
62ms
129 KB
48%
€1/mo
Optional
Hotjar
script.hotjar.com
Session Replay
52ms
57 KB
67%
€1/mo
Optional
www.rackspace.com
Other
Costly
Execution862ms
Transfer26 KB
Monthly Cost€9/mo
Unattributable
Other
Costly
Execution467ms
Transfer0 KB
Monthly Cost€5/mo
Google Tag Manager
Tag Manager
Costly
Execution356ms
Transfer193 KB
Unused33%
Monthly Cost€4/mo
HubSpot Analytics
Analytics
Costly
Execution327ms
Transfer42 KB
Monthly Cost€4/mo
www.rackspace.com
Other
Costly
Execution305ms
Transfer1 KB
Unused22%
Monthly Cost€3/mo
www.rackspace.com
Other
Optional
Execution191ms
Transfer112 KB
Unused58%
Monthly Cost€2/mo
Google Tag Manager
Tag Manager
Optional
Execution156ms
Transfer169 KB
Unused40%
Monthly Cost€2/mo
Google Tag Manager
Tag Manager
Optional
Execution152ms
Transfer175 KB
Unused40%
Monthly Cost€2/mo
Google Tag Manager
Tag Manager
Optional
Execution104ms
Transfer143 KB
Unused38%
Monthly Cost€1/mo
Google Tag Manager
Tag Manager
Optional
Execution67ms
Transfer134 KB
Unused45%
Monthly Cost€1/mo
Google Tag Manager
Tag Manager
Optional
Execution62ms
Transfer129 KB
Unused48%
Monthly Cost€1/mo
Hotjar
Session Replay
Optional
Execution52ms
Transfer57 KB
Unused67%
Monthly Cost€1/mo
These scripts may cost more than they're worth
www.rackspace.com adds 862ms and costs ~€9/month
Unattributable adds 467ms and costs ~€5/month
Google Tag Manager adds 356ms and costs ~€4/month
HubSpot Analytics adds 327ms and costs ~€4/month
www.rackspace.com adds 305ms and costs ~€3/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.rackspace.com takes 862ms 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 467ms 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 356ms 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
HubSpot Analytics takes 327ms 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.rackspace.com takes 305ms 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.rackspace.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
67% of Hotjar'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.