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
35 images, 0 KB saveable
REVIEW
35 images, 0 KB saveable
Warning::
!
https://www.hhs.gov/sites/default/files/styles/lar... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/sites/default/files/styles/lar... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/sites/default/files/styles/lar... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/sites/default/files/styles/lar... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/sites/default/files/styles/lar... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/sites/default/files/styles/lar... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/sites/default/files/styles/lar... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/sites/default/files/styles/her... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/sites/default/files/HHS-freedo... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/sites/default/files/styles/lar... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/sites/default/files/styles/lar... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/sites/default/files/styles/lar... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/themes/custom/hhs_uswds/logo-f... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/themes/custom/hhs_uswds/images... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/sites/default/files/styles/lar... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.hhs.gov/sites/default/files/styles/lar... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
35images917 KB
0oversized-0 KB
12legacy format
16missing 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
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
4 fonts (62 KB)
PASS
4 fonts (62 KB)
Info::
i
4 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
4
62 KB total
Render-blocking
0
of 4
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
JTUSjIg69CK48gW7PXoo9Wl...woff2swap
Size14 KB
Load time35 ms
Start304 ms
RiskFOUT — text flashes from fallback to web font
sourcesanspro-regular-w...woff2swap
Size20 KB
Load time21 ms
Start542 ms
RiskFOUT — text flashes from fallback to web font
JTUSjIg69CK48gW7PXoo9Wl...woff2swap
Size8 KB
Load time9 ms
Start546 ms
RiskFOUT — text flashes from fallback to web font
sourcesanspro-bold-webf...woff2swap
Size20 KB
Load time25 ms
Start546 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
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
79 requests over 1593ms
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-party4269ms · 1116KB · $57/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
Unattributable
Unattributable
Other
791ms
0 KB
—
$10/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
565ms
151 KB
33%
$8/mo
Costly
www.hhs.gov
www.hhs.gov
Other
555ms
37 KB
—
$7/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
525ms
155 KB
39%
$7/mo
Costly
www.hhs.gov
www.hhs.gov
Other
352ms
13 KB
—
$5/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
324ms
149 KB
41%
$4/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
316ms
147 KB
42%
$4/mo
Costly
www.hhs.gov
www.hhs.gov
Other
174ms
27 KB
—
$2/mo
Optional
s.go-mpulse.net
s.go-mpulse.net
Other
154ms
56 KB
48%
$2/mo
Optional
siteimproveanalytics.com
siteimproveanalytics.com
Other
132ms
90 KB
81%
$2/mo
Optional
dap.digitalgov.gov
dap.digitalgov.gov
Other
106ms
5 KB
—
$1/mo
Optional
www.hhs.gov
www.hhs.gov
Other
74ms
107 KB
—
$1/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
72ms
147 KB
72%
$1/mo
Optional
www.hhs.gov
www.hhs.gov
Other
68ms
23 KB
—
$1/mo
Optional
dap.digitalgov.gov
dap.digitalgov.gov
Other
62ms
9 KB
—
$1/mo
Optional
Unattributable
Other
Costly
Execution791ms
Transfer0 KB
Monthly Cost$10/mo
Google Tag Manager
Tag Manager
Costly
Execution565ms
Transfer151 KB
Unused33%
Monthly Cost$8/mo
www.hhs.gov
Other
Costly
Execution555ms
Transfer37 KB
Monthly Cost$7/mo
Google Tag Manager
Tag Manager
Costly
Execution525ms
Transfer155 KB
Unused39%
Monthly Cost$7/mo
www.hhs.gov
Other
Costly
Execution352ms
Transfer13 KB
Monthly Cost$5/mo
Google Tag Manager
Tag Manager
Costly
Execution324ms
Transfer149 KB
Unused41%
Monthly Cost$4/mo
Google Tag Manager
Tag Manager
Costly
Execution316ms
Transfer147 KB
Unused42%
Monthly Cost$4/mo
www.hhs.gov
Other
Optional
Execution174ms
Transfer27 KB
Monthly Cost$2/mo
s.go-mpulse.net
Other
Optional
Execution154ms
Transfer56 KB
Unused48%
Monthly Cost$2/mo
siteimproveanalytics.com
Other
Optional
Execution132ms
Transfer90 KB
Unused81%
Monthly Cost$2/mo
dap.digitalgov.gov
Other
Optional
Execution106ms
Transfer5 KB
Monthly Cost$1/mo
www.hhs.gov
Other
Optional
Execution74ms
Transfer107 KB
Monthly Cost$1/mo
Google Tag Manager
Tag Manager
Optional
Execution72ms
Transfer147 KB
Unused72%
Monthly Cost$1/mo
www.hhs.gov
Other
Optional
Execution68ms
Transfer23 KB
Monthly Cost$1/mo
dap.digitalgov.gov
Other
Optional
Execution62ms
Transfer9 KB
Monthly Cost$1/mo
These scripts may cost more than they're worth
Unattributable adds 791ms and costs ~$10/month
Google Tag Manager adds 565ms and costs ~$8/month
www.hhs.gov adds 555ms and costs ~$7/month
Google Tag Manager adds 525ms and costs ~$7/month
www.hhs.gov adds 352ms and costs ~$5/month
Google Tag Manager adds 324ms and costs ~$4/month
Google Tag Manager adds 316ms 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
Unattributable takes 791ms 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 565ms 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.hhs.gov takes 555ms 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 525ms 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.hhs.gov takes 352ms 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 324ms 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 316ms 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
81% of siteimproveanalytics.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 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.