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Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
81
GRADE
B
FIX
2
REVIEW
4
PASS
8
INFO
2

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

Mobile Desktop
26
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.

2.79 s

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

11.09 s

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

1.10 s

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

0.357

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

5.24 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.

12.29 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
16
8 PASS 4 REVIEW 2 FIX
D
JS Execution Cost
Action
3388ms total JS execution
FIX
3388ms total JS execution
Warning::
https://www.irs.gov/pub/js/js_w8fM3HiCn-P-n7TMi9se...: 943ms CPU time
Warning::
https://www.irs.gov/: 464ms CPU time
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-KV9...: 440ms CPU time
Warning::
Unattributable: 400ms CPU time
Warning::
https://www.googletagmanager.com/gtag/js?id=G-CSLL...: 333ms CPU time
Warning::
Third-party scripts: 1758ms (52% of total)

Main Thread Breakdown

Script Evaluation 48% Other 18% Style & Layout 16% Script Parsing & Compilation 11% Parse HTML & CSS 4%
ScriptTotalScriptingParse/CompileParty
https://www.irs.gov/pub/js/js_w8fM3HiCn-P-n7TMi9seyjEJrCmAhX-z8-63A6hCyVU.js?scope=footer&delta=0&language=en&theme=pup_irs&include=eJx1kWGSwyAIhS9k4pEcVGrYGnEQu-3tN2k3abLT_SO876GCQggskbi4GUtvFs7afVNMqAZiVIbysFsyXoSLGs-sTQWq3TNXBR0VOpqVK99QDkSZs1I1YeKGxb7C6PGykSi9Qh5fykRQyPBAsR4nuBFLM3jXTOW6Vf5Kk5hTRqeQbFqWv3qEL7if4Wxqr26ZHFsjT5l0nXOm4tYuPcjT99DQpswe8tBIcbggaBdsTzdcMZKyuJp7onJ4yM_2J_isJGn7LUGo6hvPoGEaJqQ06RtigmH9qwMp_dzcSpc4TDxjhYRDAOHeMO9uQ5Dl7H3XSzuo5KArB55rRkX7D_8Bj-nlkA943ms486ms22ms1st
https://www.irs.gov/464ms9ms3ms1st
https://www.googletagmanager.com/gtm.js?id=GTM-KV978ZL440ms357ms58ms3rd
Unattributable400ms15ms0ms3rd
https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L333ms262ms57ms3rd
https://www.googletagmanager.com/gtag/js?id=G-ZY6FM95CS5&cx=c&gtm=4e6460293ms217ms65ms3rd
https://www.irs.gov/pub/js/js_uQ3AXRedwNs815Y7AO31iI36vlbr_6NIRZCoLu8BbEY.js?scope=footer&delta=2&language=en&theme=pup_irs&include=eJx1kWGSwyAIhS9k4pEcVGrYGnEQu-3tN2k3abLT_SO876GCQggskbi4GUtvFs7afVNMqAZiVIbysFsyXoSLGs-sTQWq3TNXBR0VOpqVK99QDkSZs1I1YeKGxb7C6PGykSi9Qh5fykRQyPBAsR4nuBFLM3jXTOW6Vf5Kk5hTRqeQbFqWv3qEL7if4Wxqr26ZHFsjT5l0nXOm4tYuPcjT99DQpswe8tBIcbggaBdsTzdcMZKyuJp7onJ4yM_2J_isJGn7LUGo6hvPoGEaJqQ06RtigmH9qwMp_dzcSpc4TDxjhYRDAOHeMO9uQ5Dl7H3XSzuo5KArB55rRkX7D_8Bj-nlkA168ms95ms41ms1st
https://resources.digital-cloud-gov.medallia.com/wdcgov/20103/onsite/generic1774376933592.js106ms58ms47ms3rd
https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L&cx=c&gtm=4e6460101ms34ms66ms3rd
https://dap.digitalgov.gov/web-vitals/dist/web-vitals.attribution.iife.js84ms80ms2ms3rd

Showing top 10 of 11 scripts

D
JS Bundles
Action
16 scripts, 441 KB unused
FIX
16 scripts, 441 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-ZY6F...: 62 KB unused (41%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-CSLL...: 62 KB unused (42%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-KV9...: 58 KB unused (42%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.irs.gov/pub/js/js_uQ3AXRedwNs815Y7AO31...: 48 KB unused (71%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 441 KB
441 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L&cx=c&gtm=4e6460146 KB105 KB (72%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-ZY6FM95CS5&cx=c&gtm=4e6460152 KB62 KB (41%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L146 KB62 KB (42%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-KV978ZL138 KB58 KB (42%)✓3rd
https://www.irs.gov/pub/js/js_uQ3AXRedwNs815Y7AO31iI36vlbr_6NIRZCoLu8BbEY.js?scope=footer&delta=2&language=en&theme=pup_irs&include=eJx1kWGSwyAIhS9k4pEcVGrYGnEQu-3tN2k3abLT_SO876GCQggskbi4GUtvFs7afVNMqAZiVIbysFsyXoSLGs-sTQWq3TNXBR0VOpqVK99QDkSZs1I1YeKGxb7C6PGykSi9Qh5fykRQyPBAsR4nuBFLM3jXTOW6Vf5Kk5hTRqeQbFqWv3qEL7if4Wxqr26ZHFsjT5l0nXOm4tYuPcjT99DQpswe8tBIcbggaBdsTzdcMZKyuJp7onJ4yM_2J_isJGn7LUGo6hvPoGEaJqQ06RtigmH9qwMp_dzcSpc4TDxjhYRDAOHeMO9uQ5Dl7H3XSzuo5KArB55rRkX7D_8Bj-nlkA67 KB48 KB (71%)✓1st
https://resources.digital-cloud-gov.medallia.com/wdcgov/20103/onsite/generic1774376933592.js74 KB43 KB (59%)✓3rd
https://www.irs.gov/pub/js/js_w8fM3HiCn-P-n7TMi9seyjEJrCmAhX-z8-63A6hCyVU.js?scope=footer&delta=0&language=en&theme=pup_irs&include=eJx1kWGSwyAIhS9k4pEcVGrYGnEQu-3tN2k3abLT_SO876GCQggskbi4GUtvFs7afVNMqAZiVIbysFsyXoSLGs-sTQWq3TNXBR0VOpqVK99QDkSZs1I1YeKGxb7C6PGykSi9Qh5fykRQyPBAsR4nuBFLM3jXTOW6Vf5Kk5hTRqeQbFqWv3qEL7if4Wxqr26ZHFsjT5l0nXOm4tYuPcjT99DQpswe8tBIcbggaBdsTzdcMZKyuJp7onJ4yM_2J_isJGn7LUGo6hvPoGEaJqQ06RtigmH9qwMp_dzcSpc4TDxjhYRDAOHeMO9uQ5Dl7H3XSzuo5KArB55rRkX7D_8Bj-nlkA52 KB22 KB (42%)✓1st
https://static.addtoany.com/menu/modules/core.ydpp7jcu.js26 KB21 KB (82%)✓3rd
https://www.irs.gov/static_assets/js/libs/jquery.min.js30 KB20 KB (69%)✓1st
https://static.addtoany.com/menu/page.js2 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
1.5 MB transferred, 48 requests
REVIEW
1.5 MB transferred, 48 requests
Info::
Page weighs 4.1 MB (1.5 MB transferred)
Warning::
JavaScript is 851 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 851 KB
Info::
Fonts are 289 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 289 KB
Info::
48 HTTP requests
Info::
Estimated 0.32 g CO2 per page load
1.5 MB / 2.4 MB budget
1.5 MB transferred
48 requests
0.32 g CO2 per page load
JavaScript 851.0 KiB 55%
Images 295.6 KiB 19%
Fonts 289.5 KiB 19%
CSS 87.9 KiB 6%
HTML 18.6 KiB 1%
Other 1.1 KiB 0%
Other 594 B 0%
0 2.4 MB 4.9 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

Subset fonts to include only used characters, or switch to system font stacks.

Why this matters

Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).

Source: web.dev font loading

B
Third-Party Impact
45% third-party, 0 ms blocking
REVIEW
45% third-party, 0 ms blocking
Info::
Third-party code accounts for 45% of page weight (700.9 KiB of 1.5 MiB)
Info::
Third-party blocking time is low (0 ms)
55%
45%
First-party Third-party
C
Image Optimization
Action
20 images, 0 KB saveable
REVIEW
20 images, 0 KB saveable
Warning::
https://www.irs.gov/pub/Mother-father-daughter-usi... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.irs.gov/pub/image/obba-7.jpg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.irs.gov/pub/image/vita-recruit-hpsize.... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.irs.gov/pub/image/get-a-jump-on-your-t... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.irs.gov/pub/image/scamhomepage.jpg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.irs.gov/themes/custom/pup_base/IRS-Log... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.irs.gov/pub/image/hp-parents-baby.jpg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
20 images 296 KB
0 oversized -0 KB
20 legacy format
7 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

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
3 fonts (289 KB)
PASS
3 fonts (289 KB)
Info::
3 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

3

289 KB total

Render-blocking

0

of 3

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 2.0 s 4.0 s 6.0 s 8.0 s 10.0 s FCP 2.8 s LCP 11.1 shttps://www.irs.gov/themes/custom/pup_base/fonts/source-sans-pro/fonts/sourcesans3-regular.woff2sourcesans3-regular.woff2 https://www.irs.gov/themes/custom/pup_base/fonts/source-sans-pro/fonts/sourcesans3-regular.woff2 — 107.4 KiB — 0 ms — font-display: swaphttps://www.irs.gov/themes/custom/pup_base/fonts/source-sans-pro/fonts/sourcesans3-bold.woff2sourcesans3-bold.woff2 https://www.irs.gov/themes/custom/pup_base/fonts/source-sans-pro/fonts/sourcesans3-bold.woff2 — 106.4 KiB — 0 ms — font-display: swaphttps://www.irs.gov/themes/custom/pup_base/fonts/fontawesome-webfont.woff2?v=4.7.0fontawesome-webfont.woff2 https://www.irs.gov/themes/custom/pup_base/fonts/fontawesome-webfont.woff2?v=4.7.0 — 75.7 KiB — 0 ms — font-display: swap
sourcesans3-regular.woff2 woff2 swap
Size 107 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
sourcesans3-bold.woff2 woff2 swap
Size 106 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
fontawesome-webfont.woff2 woff2 swap
Size 76 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)

Fixing the unchecked items could save ~107 KB and ~214 ms

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
A+
HTTP Caching
max-age=86400 (1 day)
PASS
max-age=86400 (1 day)
Info::
Cache-Control header is set
Got: public, max-age=86400
Info::
Effective TTL: 1 day (max-age=86400)
Info::
ETag present — enables conditional (304) responses
Info::
Last-Modified header present
Cache-Control

public, max-age=86400

DirectiveValueMeaning
public—Any cache may store this response
max-age86400Cache for 1 day
Effective TTL: 86400 seconds
Network Waterfall
48 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
52% of JavaScript execution is third-party
First-party Third-party 1758ms · 661KB · €19/mo
Google Tag Manager
Tag Manager
Costly
Execution 440ms
Transfer 138 KB
Unused 42%
Monthly Cost €5/mo
Unattributable
Other
Costly
Execution 400ms
Transfer 0 KB
Monthly Cost €4/mo
Google Tag Manager
Tag Manager
Costly
Execution 333ms
Transfer 146 KB
Unused 42%
Monthly Cost €4/mo
Google Tag Manager
Tag Manager
Costly
Execution 293ms
Transfer 152 KB
Unused 41%
Monthly Cost €3/mo
resources.digital-cloud-gov.medallia.com
Other
Optional
Execution 106ms
Transfer 74 KB
Unused 59%
Monthly Cost €1/mo
Google Tag Manager
Tag Manager
Optional
Execution 101ms
Transfer 146 KB
Unused 72%
Monthly Cost €1/mo
dap.digitalgov.gov
Other
Optional
Execution 84ms
Transfer 4 KB
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • Google Tag Manager adds 440ms and costs ~€5/month
  • Unattributable adds 400ms and costs ~€4/month
  • Google Tag Manager adds 333ms and costs ~€4/month
  • Google Tag Manager adds 293ms and costs ~€3/month

52% of JavaScript execution time comes from third-party scripts.

Why this matters

Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.

Learn more ▾

Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.

Source: web.dev / HTTP Archive Web Almanac

Google Tag Manager takes 440ms 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 400ms 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 333ms 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 293ms 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

59% of resources.digital-cloud-gov.medallia.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.

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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