JavaScript is 883 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 883 KB
Info::
i
91 HTTP requests
Info::
i
Estimated 0.38 g CO2 per page load
1.8 MBtransferred
91 requests
0.38 g CO2 per page load
JavaScript882.8 KiB48%
Images762.8 KiB42%
HTML78.5 KiB4%
Fonts61.4 KiB3%
Other30.8 KiB2%
Other7.2 KiB0%
Other6.9 KiB0%
CSS2.8 KiB0%
Other1.0 KiB0%
Other721 B0%
Other0 B0%
02.4 MB4.9 MB
Approaching limit
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Why this matters
JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.
Source: web.dev
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
Image Optimization
29 images, 0 KB saveable
PASS
29 images, 0 KB saveable
Info::
✓
All images are well-optimized
29images763 KB
0oversized-0 KB
3legacy format
0missing dimensionsCLS risk
A+
Font Loading
3 fonts (61 KB)
PASS
3 fonts (61 KB)
Info::
i
3 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
3
61 KB total
Render-blocking
0
of 3
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
regular.woff2woff2swap
Size21 KB
Load time123 ms
Start344 ms
RiskFOUT — text flashes from fallback to web font
medium.woff2woff2swap
Size21 KB
Load time140 ms
Start344 ms
RiskFOUT — text flashes from fallback to web font
semibold.woff2woff2swap
Size20 KB
Load time156 ms
Start344 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
9 hints, 0 missing preconnects
PASS
9 hints, 0 missing preconnects
Info::
✓
Page uses 9 resource hint(s)
Current Resource Hints
preconnect
3
preload
6
dns-prefetch—
prefetch—
9 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
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
A
HTTP Caching
max-age=3600 (1 hour)
PASS
max-age=3600 (1 hour)
Info::
✓
Cache-Control header is set
Got: max-age=3600
Info::
✓
Effective TTL: 1 hour (max-age=3600)
Info::
i
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control
max-age=3600
Directive
Value
Meaning
max-age
3600
Cache for 1 hour
Effective TTL: 3600 seconds
Network Waterfall
91 requests over 4227ms
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-party3333ms · 611KB · $11/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.jimdo.com
www.jimdo.com
Other
916ms
45 KB
—
$3/mo
Costly
www.jimdo.com
www.jimdo.com
Other
902ms
75 KB
—
$3/mo
Costly
Unattributable
Unattributable
Other
546ms
0 KB
—
$2/mo
Costly
www.jimdo.com
www.jimdo.com
Other
231ms
86 KB
48%
$1/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
228ms
185 KB
44%
$1/mo
Costly
web.cmp.usercentrics.eu
web.cmp.usercentrics.eu
Other
134ms
56 KB
63%
$0/mo
Optional
www.jimdo.com
www.jimdo.com
Other
103ms
1 KB
—
$0/mo
Optional
www.jimdo.com
www.jimdo.com
Other
92ms
12 KB
—
$0/mo
Optional
web.cmp.usercentrics.eu
web.cmp.usercentrics.eu
Other
70ms
18 KB
—
$0/mo
Optional
www.jimdo.com
www.jimdo.com
Other
61ms
109 KB
50%
$0/mo
Optional
www.jimdo.com
www.jimdo.com
Other
51ms
23 KB
—
$0/mo
Optional
www.jimdo.com
Other
Costly
Execution916ms
Transfer45 KB
Monthly Cost$3/mo
www.jimdo.com
Other
Costly
Execution902ms
Transfer75 KB
Monthly Cost$3/mo
Unattributable
Other
Costly
Execution546ms
Transfer0 KB
Monthly Cost$2/mo
www.jimdo.com
Other
Costly
Execution231ms
Transfer86 KB
Unused48%
Monthly Cost$1/mo
Google Tag Manager
Tag Manager
Costly
Execution228ms
Transfer185 KB
Unused44%
Monthly Cost$1/mo
web.cmp.usercentrics.eu
Other
Optional
Execution134ms
Transfer56 KB
Unused63%
Monthly Cost$0/mo
www.jimdo.com
Other
Optional
Execution103ms
Transfer1 KB
Monthly Cost$0/mo
www.jimdo.com
Other
Optional
Execution92ms
Transfer12 KB
Monthly Cost$0/mo
web.cmp.usercentrics.eu
Other
Optional
Execution70ms
Transfer18 KB
Monthly Cost$0/mo
www.jimdo.com
Other
Optional
Execution61ms
Transfer109 KB
Unused50%
Monthly Cost$0/mo
www.jimdo.com
Other
Optional
Execution51ms
Transfer23 KB
Monthly Cost$0/mo
These scripts may cost more than they're worth
www.jimdo.com adds 916ms and costs ~$3/month
www.jimdo.com adds 902ms and costs ~$3/month
Unattributable adds 546ms and costs ~$2/month
www.jimdo.com adds 231ms and costs ~$1/month
Google Tag Manager adds 228ms and costs ~$1/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.jimdo.com takes 916ms 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.jimdo.com takes 902ms 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 546ms 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.jimdo.com takes 231ms 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 228ms 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
63% of web.cmp.usercentrics.eu'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.