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.
B
Page Weight Budget
1.3 MB transferred, 48 requests
REVIEW
1.3 MB transferred, 48 requests
Info::
✓
Page weighs 4.2 MB (1.3 MB transferred)
Warning::
!
JavaScript is 941 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 941 KB
Info::
✓
48 HTTP requests
Info::
i
Estimated 0.28 g CO2 per page load
1.3 MBtransferred
48 requests
0.28 g CO2 per page load
JavaScript941.1 KiB69%
Images161.3 KiB12%
Fonts123.8 KiB9%
CSS95.1 KiB7%
HTML40.1 KiB3%
Other2.5 KiB0%
Other1.6 KiB0%
Other1.4 KiB0%
Other0 B0%
02.4 MB4.9 MB
Under budget
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
C
Image Optimization
Action
11 images, 0 KB saveable
REVIEW
11 images, 0 KB saveable
Warning::
!
https://www.mass.gov/files/styles/embedded_full_wi... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.mass.gov/files/styles/embedded_full_wi... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.mass.gov/files/styles/embedded_full_wi... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
11images161 KB
0oversized-0 KB
11legacy format
3missing 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
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
3 fonts (124 KB)
PASS
3 fonts (124 KB)
Info::
i
3 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
3
124 KB total
Render-blocking
0
of 3
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
NotoSans-VF-subset.woff2woff2swap
Size55 KB
Load time27 ms
Start617 ms
RiskFOUT — text flashes from fallback to web font
NotoSansItalic-VF-subse...woff2swap
Size60 KB
Load time23 ms
Start618 ms
RiskFOUT — text flashes from fallback to web font
NotoSans-Regular-subset...woff2swap
Size9 KB
Load time15 ms
Start1.5 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
2 hints, 0 missing preconnects
PASS
2 hints, 0 missing preconnects
Info::
✓
Page uses 2 resource hint(s)
Current Resource Hints
preconnect—
preload
2
dns-prefetch—
prefetch—
2 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 2534ms
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-party3724ms · 889KB · $64/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.mass.gov
www.mass.gov
Other
1660ms
40 KB
—
$29/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
417ms
159 KB
37%
$7/mo
Costly
translate.googleapis.com
translate.googleapis.com
Other
287ms
119 KB
78%
$5/mo
Costly
Unattributable
Unattributable
Other
280ms
0 KB
—
$5/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
280ms
160 KB
42%
$5/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
245ms
158 KB
42%
$4/mo
Costly
www.mass.gov
www.mass.gov
Other
178ms
139 KB
67%
$3/mo
Optional
js-agent.newrelic.com
js-agent.newrelic.com
Other
156ms
34 KB
—
$3/mo
Optional
www.mass.gov
www.mass.gov
Other
151ms
77 KB
77%
$3/mo
Optional
www.mass.gov
www.mass.gov
Other
69ms
3 KB
—
$1/mo
Optional
www.mass.gov
Other
Costly
Execution1660ms
Transfer40 KB
Monthly Cost$29/mo
Google Tag Manager
Tag Manager
Costly
Execution417ms
Transfer159 KB
Unused37%
Monthly Cost$7/mo
translate.googleapis.com
Other
Costly
Execution287ms
Transfer119 KB
Unused78%
Monthly Cost$5/mo
Unattributable
Other
Costly
Execution280ms
Transfer0 KB
Monthly Cost$5/mo
Google Tag Manager
Tag Manager
Costly
Execution280ms
Transfer160 KB
Unused42%
Monthly Cost$5/mo
Google Tag Manager
Tag Manager
Costly
Execution245ms
Transfer158 KB
Unused42%
Monthly Cost$4/mo
www.mass.gov
Other
Optional
Execution178ms
Transfer139 KB
Unused67%
Monthly Cost$3/mo
js-agent.newrelic.com
Other
Optional
Execution156ms
Transfer34 KB
Monthly Cost$3/mo
www.mass.gov
Other
Optional
Execution151ms
Transfer77 KB
Unused77%
Monthly Cost$3/mo
www.mass.gov
Other
Optional
Execution69ms
Transfer3 KB
Monthly Cost$1/mo
These scripts may cost more than they're worth
www.mass.gov adds 1660ms and costs ~$29/month
Google Tag Manager adds 417ms and costs ~$7/month
translate.googleapis.com adds 287ms and costs ~$5/month
Unattributable adds 280ms and costs ~$5/month
Google Tag Manager adds 280ms and costs ~$5/month
Google Tag Manager adds 245ms 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.mass.gov takes 1660ms 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 417ms 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
translate.googleapis.com takes 287ms 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
78% of translate.googleapis.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
Unattributable takes 280ms 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 280ms 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 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
67% of www.mass.gov'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
77% of www.mass.gov'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.