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https://www.usa.gov

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
76
GRADE
C
FIX
1
REVIEW
5
PASS
6
INFO
2

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

Mobile Desktop
99
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
100
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.

474 ms

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

747 ms

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

101 ms

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

0.029

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

668 ms

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

1.96 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 5 REVIEW 1 FIX
D
JS Bundles
Action
14 scripts, 382 KB unused
FIX
14 scripts, 382 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/gtm.js?id=GTM-THH...: 65 KB unused (53%)
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/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...: 54 KB unused (40%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 382 KB
382 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/gtm.js?id=GTM-THHB6TNL&gtm=4e6411122 KB65 KB (53%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-GXFTMLX26S&cx=c&gtm=4e6411151 KB62 KB (41%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L146 KB61 KB (42%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-W8LW6DB137 KB54 KB (40%)✓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
1.2 MB transferred, 40 requests
REVIEW
1.2 MB transferred, 40 requests
Info::
Page weighs 3.5 MB (1.2 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::
40 HTTP requests
Info::
Estimated 0.25 g CO2 per page load
1.2 MB / 2.4 MB budget
1.2 MB transferred
40 requests
0.25 g CO2 per page load
JavaScript 786.8 KiB 63%
Images 223.5 KiB 18%
Fonts 99.1 KiB 8%
CSS 90.8 KiB 7%
Other 27.6 KiB 2%
HTML 9.9 KiB 1%
Other 852 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
Third-Party Impact
59% third-party, 0 ms blocking
REVIEW
59% third-party, 0 ms blocking
Warning::
Third-party code accounts for 59% of page weight (727.0 KiB of 1.2 MiB)
Info::
Third-party blocking time is low (0 ms)
41%
59%
First-party Third-party
B
Image Optimization
13 images, 0 KB saveable
REVIEW
13 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.
13 images 223 KB
0 oversized -0 KB
13 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

B
JS Execution Cost
781ms total JS execution
REVIEW
781ms total JS execution
Info::
https://www.usa.gov/: 160ms CPU time
Info::
https://www.googletagmanager.com/gtm.js?id=GTM-W8L...: 158ms CPU time
Info::
Unattributable: 137ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-CSLL...: 105ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-GXFT...: 104ms CPU time
Warning::
Third-party scripts: 558ms (72% of total)

Main Thread Breakdown

Script Evaluation 51% Other 16% Style & Layout 14% Script Parsing & Compilation 12% Parse HTML & CSS 4%
ScriptTotalScriptingParse/CompileParty
https://www.usa.gov/160ms5ms2ms1st
https://www.googletagmanager.com/gtm.js?id=GTM-W8LW6DB158ms131ms24ms3rd
Unattributable137ms3ms0ms3rd
https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L105ms87ms18ms3rd
https://www.googletagmanager.com/gtag/js?id=G-GXFTMLX26S&cx=c&gtm=4e6411104ms83ms20ms3rd
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-KSUXQ2yOLF9knAojFEt9T3eTLuV9AYiJkrD63ms47ms9ms1st
https://www.googletagmanager.com/gtm.js?id=GTM-THHB6TNL&gtm=4e641154ms37ms17ms3rd
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 500 ms 1.0 s FCP 474 ms LCP 747 mshttps://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
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
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
40 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
72% of JavaScript execution is third-party
First-party Third-party 558ms · 556KB · €9/mo
Google Tag Manager
Tag Manager
Optional
Execution 158ms
Transfer 137 KB
Unused 40%
Monthly Cost €3/mo
Unattributable
Other
Optional
Execution 137ms
Transfer 0 KB
Monthly Cost €2/mo
Google Tag Manager
Tag Manager
Optional
Execution 105ms
Transfer 146 KB
Unused 42%
Monthly Cost €2/mo
Google Tag Manager
Tag Manager
Optional
Execution 104ms
Transfer 151 KB
Unused 41%
Monthly Cost €2/mo
Google Tag Manager
Tag Manager
Optional
Execution 54ms
Transfer 122 KB
Unused 53%
Monthly Cost €1/mo

72% 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

53% 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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