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Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
76
GRADE
C
FIX
3
REVIEW
3
PASS
6
INFO
2

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop
47
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
98
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
100
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

1.79 s

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

8.69 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

1.60 s

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.000

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

3.31 s

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

9.13 s

Page Load Progression

375 ms
750 ms
1.1 s
1.5 s
1.9 s
2.2 s
2.6 s
3.0 s
Checks
14
6 PASS 3 REVIEW 3 FIX
D
Third-Party Impact
Action
66% third-party, 0 ms blocking
FIX
66% third-party, 0 ms blocking
Warning::
Third-party code accounts for 66% of page weight (727.6 KiB of 1.1 MiB)
Info::
Third-party blocking time is low (0 ms)
34%
66%
First-party Third-party
F
JS Execution Cost
Action
3952ms total JS execution
FIX
3952ms total JS execution
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-W8L...: 670ms CPU time
Warning::
Unattributable: 569ms CPU time
Warning::
https://www.usa.gov/: 512ms CPU time
Warning::
https://www.googletagmanager.com/gtag/js?id=G-GXFT...: 486ms CPU time
Warning::
https://www.googletagmanager.com/gtag/js?id=G-CSLL...: 427ms CPU time
Warning::
Third-party scripts: 2982ms (75% of total)

Main Thread Breakdown

Script Evaluation 54% Other 15% Style & Layout 13% Script Parsing & Compilation 11% Parse HTML & CSS 4%
ScriptTotalScriptingParse/CompileParty
https://www.googletagmanager.com/gtm.js?id=GTM-W8LW6DB670ms564ms81ms3rd
Unattributable569ms16ms0ms3rd
https://www.usa.gov/512ms22ms8ms1st
https://www.googletagmanager.com/gtag/js?id=G-GXFTMLX26S&cx=c&gtm=4e6411486ms405ms78ms3rd
https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L427ms338ms84ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-THHB6TNL&gtm=4e6411319ms233ms69ms3rd
https://www.usa.gov/sites/default/files/js/js_zKYkgcCe8nw2Ew0MHhQW_VNFJZmUAiJ5nZAYvm8UyfU.js?scope=footer&delta=0&language=en&theme=usagov&include=eJx1i0EOwjAMBD9Emz9wQ-IPlpsYE0jsynGL2tcTUThy3JnZqEYhap1VSLyNS0PWdRgaocX7hHY6SOCiE5ah-Vay8I8W3LerYjrzpSLTF4PrDIJrZvSsApVkCf8VPFo_vlKD-KSUXQ2yOLF9knAojFEt9T3eTLuV9AYiJkrD256ms182ms37ms1st
https://dap.digitalgov.gov/web-vitals/dist/web-vitals.attribution.iife.js214ms193ms3ms3rd
https://www.usa.gov/sites/default/files/css/css_RS0lu12kxAKVlYtiIn6qpAq__BevSHCXAmcrTugppls.css?delta=1&language=en&theme=usagov&include=eJwdyUsKwCAMRdEN2WZJEjGEQKKD5wd3X-zkDs7FwZCgwpA0wZlrWMsYxwUUx61c1r5IvRf25y5rmpbJBv19o9fp8gFn6R2f138ms0ms0ms1st
https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L&cx=c&gtm=4e6411126ms51ms74ms3rd

Showing top 10 of 13 scripts

D
JS Bundles
Action
14 scripts, 381 KB unused
FIX
14 scripts, 381 KB unused
Warning::
https://www.googletagmanager.com/gtag/js?id=G-CSLL...: 105 KB unused (72%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-GXFT...: 62 KB unused (41%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-THH...: 62 KB unused (51%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-CSLL...: 61 KB unused (42%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-W8L...: 56 KB unused (41%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 381 KB
381 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L&cx=c&gtm=4e6411146 KB105 KB (72%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-GXFTMLX26S&cx=c&gtm=4e6411151 KB62 KB (41%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-THHB6TNL&gtm=4e6411123 KB62 KB (51%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L146 KB61 KB (42%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-W8LW6DB137 KB56 KB (41%)✓3rd
https://www.usa.gov/sites/default/files/js/js_zKYkgcCe8nw2Ew0MHhQW_VNFJZmUAiJ5nZAYvm8UyfU.js?scope=footer&delta=0&language=en&theme=usagov&include=eJx1i0EOwjAMBD9Emz9wQ-IPlpsYE0jsynGL2tcTUThy3JnZqEYhap1VSLyNS0PWdRgaocX7hHY6SOCiE5ah-Vay8I8W3LerYjrzpSLTF4PrDIJrZvSsApVkCf8VPFo_vlKD-KSUXQ2yOLF9knAojFEt9T3eTLuV9AYiJkrD58 KB35 KB (61%)✓1st
https://siteimproveanalytics.com/js/siteanalyze_51567.js9 KB—✓3rd
https://script.crazyegg.com/pages/scripts/0007/9651.js0 KB—✓3rd
https://www.usa.gov/themes/custom/usagov/scripts/modifyMobileNav.js2 KB—✓1st
https://dap.digitalgov.gov/Universal-Federated-Analytics-Min.js?agency=GSA&subagency=TTS9 KB—✓3rd

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

B
Page Weight Budget
1.1 MB transferred, 42 requests
REVIEW
1.1 MB transferred, 42 requests
Info::
Page weighs 3.4 MB (1.1 MB transferred)
Warning::
JavaScript is 787 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 787 KB
Info::
42 HTTP requests
Info::
Estimated 0.22 g CO2 per page load
1.1 MB / 2.4 MB budget
1.1 MB transferred
42 requests
0.22 g CO2 per page load
JavaScript 787.4 KiB 72%
Fonts 99.1 KiB 9%
CSS 90.8 KiB 8%
Images 81.3 KiB 7%
Other 27.6 KiB 3%
HTML 10.7 KiB 1%
Other 884 B 0%
Other 594 B 0%
0 2.4 MB 4.9 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

B
Image Optimization
15 images, 0 KB saveable
REVIEW
15 images, 0 KB saveable
Warning::
https://www.usa.gov/themes/custom/usagov/images/to... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
15 images 81 KB
0 oversized -0 KB
15 legacy format
1 missing dimensions CLS 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

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
5 fonts (99 KB)
PASS
5 fonts (99 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

5

99 KB total

Render-blocking

0

of 5

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 1.0 s 2.0 s 3.0 s 4.0 s 5.0 s 6.0 s 7.0 s 8.0 s 9.0 s FCP 1.8 s LCP 8.7 shttps://www.usa.gov/themes/custom/usagov/fonts/source-sans-pro/sourcesanspro-regular-webfont.woff2sourcesanspro-regular-w... https://www.usa.gov/themes/custom/usagov/fonts/source-sans-pro/sourcesanspro-regular-webfont.woff2 — 20.5 KiB — 0 ms — font-display: swaphttps://www.usa.gov/themes/custom/usagov/fonts/source-sans-pro/sourcesanspro-bold-webfont.woff2sourcesanspro-bold-webf... https://www.usa.gov/themes/custom/usagov/fonts/source-sans-pro/sourcesanspro-bold-webfont.woff2 — 20.4 KiB — 0 ms — font-display: swaphttps://www.usa.gov/themes/custom/usagov/fonts/merriweather/Latin-Merriweather-Bold.woff2Latin-Merriweather-Bold... https://www.usa.gov/themes/custom/usagov/fonts/merriweather/Latin-Merriweather-Bold.woff2 — 21.3 KiB — 0 ms — font-display: swaphttps://www.usa.gov/themes/custom/usagov/fonts/source-sans-pro/sourcesanspro-semibold-webfont.woff2sourcesanspro-semibold-... https://www.usa.gov/themes/custom/usagov/fonts/source-sans-pro/sourcesanspro-semibold-webfont.woff2 — 20.5 KiB — 0 ms — font-display: swaphttps://www.usa.gov/themes/custom/usagov/fonts/source-sans-pro/sourcesanspro-italic-webfont.woff2sourcesanspro-italic-we... https://www.usa.gov/themes/custom/usagov/fonts/source-sans-pro/sourcesanspro-italic-webfont.woff2 — 16.5 KiB — 0 ms — font-display: swap
sourcesanspro-regular-w... woff2 swap
Size 21 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
sourcesanspro-bold-webf... woff2 swap
Size 20 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Latin-Merriweather-Bold... woff2 swap
Size 21 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
sourcesanspro-semibold-... woff2 swap
Size 20 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
sourcesanspro-italic-we... woff2 swap
Size 16 KB
Load time 0 ms
Start 0 ms
Risk FOUT — 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
13 hints, 0 missing preconnects
PASS
13 hints, 0 missing preconnects
Info::
Page uses 13 resource hint(s)

Current Resource Hints

preconnect
2
preload
+1
11
dns-prefetch
—
prefetch
—

13 resource hints configured

A+
HTTP Caching
max-age=900 (15 minutes)
PASS
max-age=900 (15 minutes)
Info::
Cache-Control header is set
Got: max-age=900
Info::
Effective TTL: 15 minutes (max-age=900)
Info::
ETag present — enables conditional (304) responses
Info::
Last-Modified header present
Cache-Control

max-age=900

DirectiveValueMeaning
max-age900Cache for 15 minutes
Effective TTL: 900 seconds
Network Waterfall
42 requests over 0ms
INFO

Performance analysis not available for this result.

Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
75% of JavaScript execution is third-party
First-party Third-party 2982ms · 726KB · €48/mo
Google Tag Manager
Tag Manager
Costly
Execution 670ms
Transfer 137 KB
Unused 41%
Monthly Cost €11/mo
Unattributable
Other
Costly
Execution 569ms
Transfer 0 KB
Monthly Cost €9/mo
Google Tag Manager
Tag Manager
Costly
Execution 486ms
Transfer 151 KB
Unused 41%
Monthly Cost €8/mo
Google Tag Manager
Tag Manager
Costly
Execution 427ms
Transfer 146 KB
Unused 42%
Monthly Cost €7/mo
Google Tag Manager
Tag Manager
Costly
Execution 319ms
Transfer 123 KB
Unused 51%
Monthly Cost €5/mo
dap.digitalgov.gov
Other
Costly
Execution 214ms
Transfer 4 KB
Monthly Cost €3/mo
Google Tag Manager
Tag Manager
Optional
Execution 126ms
Transfer 146 KB
Unused 72%
Monthly Cost €2/mo
siteimproveanalytics.com
Other
Optional
Execution 90ms
Transfer 9 KB
Monthly Cost €1/mo
dap.digitalgov.gov
Other
Optional
Execution 82ms
Transfer 9 KB
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • Google Tag Manager adds 670ms and costs ~€11/month
  • Unattributable adds 569ms and costs ~€9/month
  • Google Tag Manager adds 486ms and costs ~€8/month
  • Google Tag Manager adds 427ms and costs ~€7/month
  • Google Tag Manager adds 319ms and costs ~€5/month
  • dap.digitalgov.gov adds 214ms and costs ~€3/month

75% 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

Google Tag Manager takes 670ms 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 569ms 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 486ms 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 427ms 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 319ms 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

51% 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

dap.digitalgov.gov takes 214ms 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

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.

Source: web.dev

How third-party costs are calculated

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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