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
Page Weight Budget
Action
1.9 MB transferred, 48 requests
REVIEW
1.9 MB transferred, 48 requests
Info::
i
Page weighs 6.9 MB (1.9 MB transferred)
Warning::
!
JavaScript is 1.2 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.2 MB
Info::
✓
48 HTTP requests
Info::
i
Estimated 0.40 g CO2 per page load
1.9 MBtransferred
48 requests
0.40 g CO2 per page load
JavaScript1.2 MiB65%
Images416.6 KiB22%
HTML116.9 KiB6%
CSS96.9 KiB5%
Other21.4 KiB1%
Other16.2 KiB1%
Other649 B0%
Other225 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
B
Image Optimization
6 images, 0 KB saveable
REVIEW
6 images, 0 KB saveable
Info::
✓
All images are well-optimized
6images417 KB
0oversized-0 KB
5legacy format
0missing dimensionsCLS risk
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
No web fonts (system fonts)
PASS
No web fonts (system fonts)
Info::
✓
No web fonts loaded — system fonts are fastest
No web fonts loaded — system fonts are optimal.
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—
preload
9
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
Network Waterfall
48 requests over 3715ms
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-party5285ms · 1142KB · $70/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
static.cdninstagram.com
static.cdninstagram.com
Other
3136ms
72 KB
48%
$42/mo
Costly
www.threads.com
www.threads.com
Other
641ms
117 KB
—
$9/mo
Costly
Unattributable
Unattributable
Other
539ms
0 KB
—
$7/mo
Costly
static.cdninstagram.com
static.cdninstagram.com
Other
295ms
188 KB
48%
$4/mo
Costly
static.cdninstagram.com
static.cdninstagram.com
Other
264ms
233 KB
43%
$4/mo
Costly
static.cdninstagram.com
static.cdninstagram.com
Other
139ms
191 KB
50%
$2/mo
Optional
static.cdninstagram.com
static.cdninstagram.com
Other
132ms
184 KB
60%
$2/mo
Optional
static.cdninstagram.com
static.cdninstagram.com
Other
78ms
126 KB
83%
$1/mo
Optional
static.cdninstagram.com
static.cdninstagram.com
Other
61ms
29 KB
72%
$1/mo
Optional
static.cdninstagram.com
Other
Costly
Execution3136ms
Transfer72 KB
Unused48%
Monthly Cost$42/mo
www.threads.com
Other
Costly
Execution641ms
Transfer117 KB
Monthly Cost$9/mo
Unattributable
Other
Costly
Execution539ms
Transfer0 KB
Monthly Cost$7/mo
static.cdninstagram.com
Other
Costly
Execution295ms
Transfer188 KB
Unused48%
Monthly Cost$4/mo
static.cdninstagram.com
Other
Costly
Execution264ms
Transfer233 KB
Unused43%
Monthly Cost$4/mo
static.cdninstagram.com
Other
Optional
Execution139ms
Transfer191 KB
Unused50%
Monthly Cost$2/mo
static.cdninstagram.com
Other
Optional
Execution132ms
Transfer184 KB
Unused60%
Monthly Cost$2/mo
static.cdninstagram.com
Other
Optional
Execution78ms
Transfer126 KB
Unused83%
Monthly Cost$1/mo
static.cdninstagram.com
Other
Optional
Execution61ms
Transfer29 KB
Unused72%
Monthly Cost$1/mo
These scripts may cost more than they're worth
static.cdninstagram.com adds 3136ms and costs ~$42/month
www.threads.com adds 641ms and costs ~$9/month
Unattributable adds 539ms and costs ~$7/month
static.cdninstagram.com adds 295ms and costs ~$4/month
static.cdninstagram.com adds 264ms 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
static.cdninstagram.com takes 3136ms 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.threads.com takes 641ms 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 539ms 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
static.cdninstagram.com takes 295ms 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
static.cdninstagram.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
50% of static.cdninstagram.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
60% of static.cdninstagram.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
83% of static.cdninstagram.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
72% of static.cdninstagram.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.