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
29 images, 0 KB saveable
REVIEW
29 images, 0 KB saveable
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.xero.com/content/dam/xero/pilot-images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
29images684 KB
0oversized-0 KB
8legacy format
15missing 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
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 (71 KB)
PASS
2 fonts (71 KB)
Info::
i
2 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
2
71 KB total
Render-blocking
0
of 2
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
national2-web-regular.w...woff2swap
Size34 KB
Load time31 ms
Start681 ms
RiskFOUT — text flashes from fallback to web font
national2-web-bold.woff2woff2swap
Size37 KB
Load time73 ms
Start682 ms
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
131 requests over 14466ms
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-party3027ms · 1787KB · €48/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.xero.com
www.xero.com
Other
1206ms
65 KB
—
€19/mo
Costly
www.xero.com
www.xero.com
Other
392ms
64 KB
—
€6/mo
Costly
Unattributable
Unattributable
Other
245ms
0 KB
—
€4/mo
Costly
www.xero.com
www.xero.com
Other
234ms
1 KB
21%
€4/mo
Costly
cdn-au.onetrust.com
cdn-au.onetrust.com
Other
142ms
130 KB
55%
€2/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
139ms
222 KB
31%
€2/mo
Optional
www.xero.com
www.xero.com
Other
136ms
222 KB
57%
€2/mo
Optional
www.xero.com
www.xero.com
Other
110ms
244 KB
70%
€2/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
97ms
146 KB
39%
€2/mo
Optional
Stripe
js.stripe.com
Payment
85ms
220 KB
73%
€1/mo
Essential
Google Tag Manager
www.googletagmanager.com
Tag Manager
63ms
170 KB
52%
€1/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
61ms
152 KB
55%
€1/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
59ms
151 KB
55%
€1/mo
Optional
js-agent.newrelic.com
js-agent.newrelic.com
Other
58ms
0 KB
—
€1/mo
Optional
www.xero.com
Other
Costly
Execution1206ms
Transfer65 KB
Monthly Cost€19/mo
www.xero.com
Other
Costly
Execution392ms
Transfer64 KB
Monthly Cost€6/mo
Unattributable
Other
Costly
Execution245ms
Transfer0 KB
Monthly Cost€4/mo
www.xero.com
Other
Costly
Execution234ms
Transfer1 KB
Unused21%
Monthly Cost€4/mo
cdn-au.onetrust.com
Other
Optional
Execution142ms
Transfer130 KB
Unused55%
Monthly Cost€2/mo
Google Tag Manager
Tag Manager
Optional
Execution139ms
Transfer222 KB
Unused31%
Monthly Cost€2/mo
www.xero.com
Other
Optional
Execution136ms
Transfer222 KB
Unused57%
Monthly Cost€2/mo
www.xero.com
Other
Optional
Execution110ms
Transfer244 KB
Unused70%
Monthly Cost€2/mo
Google Tag Manager
Tag Manager
Optional
Execution97ms
Transfer146 KB
Unused39%
Monthly Cost€2/mo
Stripe
Payment
Essential
Execution85ms
Transfer220 KB
Unused73%
Monthly Cost€1/mo
Google Tag Manager
Tag Manager
Optional
Execution63ms
Transfer170 KB
Unused52%
Monthly Cost€1/mo
Google Tag Manager
Tag Manager
Optional
Execution61ms
Transfer152 KB
Unused55%
Monthly Cost€1/mo
Google Tag Manager
Tag Manager
Optional
Execution59ms
Transfer151 KB
Unused55%
Monthly Cost€1/mo
js-agent.newrelic.com
Other
Optional
Execution58ms
Transfer0 KB
Monthly Cost€1/mo
These scripts may cost more than they're worth
www.xero.com adds 1206ms and costs ~€19/month
www.xero.com adds 392ms and costs ~€6/month
Unattributable adds 245ms and costs ~€4/month
www.xero.com adds 234ms and costs ~€4/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.xero.com takes 1206ms 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.xero.com takes 392ms 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 245ms 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.xero.com takes 234ms 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
55% of cdn-au.onetrust.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
57% of www.xero.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
70% of www.xero.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
73% of Stripe'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
52% 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
55% 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
55% 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.