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
51 images, 0 KB saveable
REVIEW
51 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/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/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.
51images692 KB
0oversized-0 KB
48legacy format
29missing 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
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
8 fonts (222 KB)
PASS
8 fonts (222 KB)
Info::
i
8 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
8
222 KB total
Render-blocking
0
of 8
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size34 KB
Load time43 ms
Start580 ms
RiskFOUT — text flashes from fallback to web font
open-sans-v18-latin-reg...woff2swap
Size14 KB
Load time40 ms
Start685 ms
RiskFOUT — text flashes from fallback to web font
open-sans-v18-latin-700...woff2swap
Size15 KB
Load time50 ms
Start686 ms
RiskFOUT — text flashes from fallback to web font
open-sans-v18-latin-600...woff2swap
Size15 KB
Load time54 ms
Start686 ms
RiskFOUT — text flashes from fallback to web font
slick.woffwoffswap
Size2 KB
Load time52 ms
Start692 ms
RiskFOUT — text flashes from fallback to web font
Convert to woff2 for ~30% smaller file size
rswebfonts.woff2woff2swap
Size62 KB
Load time39 ms
Start694 ms
RiskFOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size39 KB
Load time50 ms
Start1.5 s
RiskFOUT — text flashes from fallback to web font
memvYaGs126MiZpBA-UvWbX...woff2swap
Size42 KB
Load time23 ms
Start2.5 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
1 hints, 0 missing preconnects
PASS
1 hints, 0 missing preconnects
Info::
✓
Page uses 1 resource hint(s)
Current Resource Hints
preconnect—
preload—
dns-prefetch
1
prefetch—
1 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
162 requests over 5957ms
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-party13642ms · 1336KB · €148/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.rackspace.com
www.rackspace.com
Other
3203ms
26 KB
—
€35/mo
Costly
Unattributable
Unattributable
Other
1791ms
0 KB
—
€19/mo
Costly
www.rackspace.com
www.rackspace.com
Other
1615ms
1 KB
22%
€18/mo
Costly
HubSpot Analytics
js.hs-analytics.net
Analytics
1256ms
42 KB
—
€14/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
1171ms
193 KB
33%
€13/mo
Costly
www.rackspace.com
www.rackspace.com
Other
1105ms
112 KB
58%
€12/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
765ms
169 KB
40%
€8/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
538ms
143 KB
38%
€6/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
477ms
175 KB
40%
€5/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
311ms
134 KB
45%
€3/mo
Costly
js.hubspot.com
js.hubspot.com
Other
264ms
28 KB
—
€3/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
263ms
129 KB
48%
€3/mo
Costly
js.hscollectedforms.net
js.hscollectedforms.net
Other
207ms
26 KB
—
€2/mo
Costly
Hotjar
script.hotjar.com
Session Replay
179ms
57 KB
67%
€2/mo
Optional
Google Analytics
www.google-analytics.com
Analytics
145ms
21 KB
—
€2/mo
Optional
js.hs-banner.com
js.hs-banner.com
Other
139ms
26 KB
—
€2/mo
Optional
abm-tracking.demandscience.com
abm-tracking.demandscience.com
Other
104ms
3 KB
—
€1/mo
Optional
www.rackspace.com
www.rackspace.com
Other
56ms
45 KB
—
€1/mo
Optional
www.rackspace.com
www.rackspace.com
Other
52ms
4 KB
—
€1/mo
Optional
www.rackspace.com
Other
Costly
Execution3203ms
Transfer26 KB
Monthly Cost€35/mo
Unattributable
Other
Costly
Execution1791ms
Transfer0 KB
Monthly Cost€19/mo
www.rackspace.com
Other
Costly
Execution1615ms
Transfer1 KB
Unused22%
Monthly Cost€18/mo
HubSpot Analytics
Analytics
Costly
Execution1256ms
Transfer42 KB
Monthly Cost€14/mo
Google Tag Manager
Tag Manager
Costly
Execution1171ms
Transfer193 KB
Unused33%
Monthly Cost€13/mo
www.rackspace.com
Other
Costly
Execution1105ms
Transfer112 KB
Unused58%
Monthly Cost€12/mo
Google Tag Manager
Tag Manager
Costly
Execution765ms
Transfer169 KB
Unused40%
Monthly Cost€8/mo
Google Tag Manager
Tag Manager
Costly
Execution538ms
Transfer143 KB
Unused38%
Monthly Cost€6/mo
Google Tag Manager
Tag Manager
Costly
Execution477ms
Transfer175 KB
Unused40%
Monthly Cost€5/mo
Google Tag Manager
Tag Manager
Costly
Execution311ms
Transfer134 KB
Unused45%
Monthly Cost€3/mo
js.hubspot.com
Other
Costly
Execution264ms
Transfer28 KB
Monthly Cost€3/mo
Google Tag Manager
Tag Manager
Costly
Execution263ms
Transfer129 KB
Unused48%
Monthly Cost€3/mo
js.hscollectedforms.net
Other
Costly
Execution207ms
Transfer26 KB
Monthly Cost€2/mo
Hotjar
Session Replay
Optional
Execution179ms
Transfer57 KB
Unused67%
Monthly Cost€2/mo
Google Analytics
Analytics
Optional
Execution145ms
Transfer21 KB
Monthly Cost€2/mo
js.hs-banner.com
Other
Optional
Execution139ms
Transfer26 KB
Monthly Cost€2/mo
abm-tracking.demandscience.com
Other
Optional
Execution104ms
Transfer3 KB
Monthly Cost€1/mo
www.rackspace.com
Other
Optional
Execution56ms
Transfer45 KB
Monthly Cost€1/mo
www.rackspace.com
Other
Optional
Execution52ms
Transfer4 KB
Monthly Cost€1/mo
These scripts may cost more than they're worth
www.rackspace.com adds 3203ms and costs ~€35/month
Unattributable adds 1791ms and costs ~€19/month
www.rackspace.com adds 1615ms and costs ~€18/month
HubSpot Analytics adds 1256ms and costs ~€14/month
Google Tag Manager adds 1171ms and costs ~€13/month
www.rackspace.com adds 1105ms and costs ~€12/month
Google Tag Manager adds 765ms and costs ~€8/month
Google Tag Manager adds 538ms and costs ~€6/month
Google Tag Manager adds 477ms and costs ~€5/month
Google Tag Manager adds 311ms and costs ~€3/month
js.hubspot.com adds 264ms and costs ~€3/month
Google Tag Manager adds 263ms and costs ~€3/month
js.hscollectedforms.net adds 207ms 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.rackspace.com takes 3203ms 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 1791ms 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 1615ms 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 1256ms 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 1171ms 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 1105ms 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
Google Tag Manager takes 765ms 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 538ms 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 477ms 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 311ms 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
js.hubspot.com takes 264ms 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 263ms 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
js.hscollectedforms.net takes 207ms 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
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.