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Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
78
GRADE
C
FIX
3
REVIEW
3
PASS
8
INFO
2

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

Mobile Desktop
57
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
91
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
92
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.

2.29 s

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

4.77 s

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

1.12 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.

2.97 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.

9.50 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 3 REVIEW 3 FIX
D
Page Weight Budget
Action
2.1 MB transferred, 105 requests
FIX
2.1 MB transferred, 105 requests
Info::
Page weighs 4.1 MB (2.1 MB transferred)
Warning::
JavaScript is 807 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 807 KB
Info::
Fonts are 218 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 218 KB
Warning::
105 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 0.44 g CO2 per page load
2.1 MB / 2.4 MB budget
2.1 MB transferred
105 requests
0.44 g CO2 per page load
Images 948.8 KiB 44%
JavaScript 806.6 KiB 38%
Fonts 217.9 KiB 10%
CSS 106.7 KiB 5%
HTML 42.1 KiB 2%
Other 7.3 KiB 0%
Other 4.4 KiB 0%
Other 2.6 KiB 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

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Why this matters

High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.

Source: web.dev

D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (2.1 MiB of 2.1 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
JS Execution Cost
Action
3975ms total JS execution
FIX
3975ms total JS execution
Warning::
https://duckduckgo.com/_next/static/chunks/framewo...: 2187ms CPU time
Warning::
Unattributable: 582ms CPU time
Warning::
https://duckduckgo.com/: 357ms CPU time
Warning::
https://duckduckgo.com/_next/static/chunks/pages/%...: 309ms CPU time
Warning::
https://duckduckgo.com/_next/static/chunks/pages/_...: 271ms CPU time
Warning::
Third-party scripts: 3975ms (100% of total)

Main Thread Breakdown

Script Evaluation 52% Other 18% Style & Layout 18% Script Parsing & Compilation 8%
ScriptTotalScriptingParse/CompileParty
https://duckduckgo.com/_next/static/chunks/framework-676ac3c731e183b1.js2187ms1386ms26ms3rd
Unattributable582ms19ms0ms3rd
https://duckduckgo.com/357ms83ms13ms3rd
https://duckduckgo.com/_next/static/chunks/pages/%5Blocale%5D/home/mobile-229cc7f291dc4506.js309ms308ms0ms3rd
https://duckduckgo.com/_next/static/chunks/pages/_app-ab8d89ae7e89fc12.js271ms213ms57ms3rd
https://duckduckgo.com/_next/static/chunks/main-e01866fd58586c66.js180ms150ms29ms3rd
https://duckduckgo.com/_next/static/chunks/9166-f79cf75186244b55.js89ms26ms13ms3rd
C
Image Optimization
Action
36 images, 0 KB saveable
REVIEW
36 images, 0 KB saveable
Warning::
https://duckduckgo.com/static-assets/image/pages/a... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://duckduckgo.com/static-assets/image/pages/a... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://duckduckgo.com/static-assets/image/pages/a... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://duckduckgo.com/static-assets/image/pages/a... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://duckduckgo.com/static-assets/image/pages/a... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://duckduckgo.com/static-assets/image/pages/a... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://duckduckgo.com/static-assets/image/pages/a... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://duckduckgo.com/static-assets/image/pages/a... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://duckduckgo.com/static-assets/image/pages/a... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://duckduckgo.com/_next/static/media/google-p... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://duckduckgo.com/static-assets/image/pages/a... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
36 images 949 KB
0 oversized -0 KB
29 legacy format
11 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

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
JS Bundles
Action
34 scripts, 278 KB unused
REVIEW
34 scripts, 278 KB unused
Warning::
https://duckduckgo.com/_next/static/chunks/2912-e3...: 63 KB unused (88%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://duckduckgo.com/_next/static/chunks/598-7ab...: 51 KB unused (87%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://duckduckgo.com/_next/static/chunks/7500-ac...: 33 KB unused (86%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://duckduckgo.com/_next/static/chunks/9489-16...: 33 KB unused (62%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://duckduckgo.com/_next/static/chunks/pages/_...: 27 KB unused (29%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 278 KB
278 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://duckduckgo.com/_next/static/chunks/2912-e30e11398dfb07de.js74 KB63 KB (88%)✓3rd
https://duckduckgo.com/_next/static/chunks/598-7ab10e38d8092144.js60 KB51 KB (87%)✓3rd
https://duckduckgo.com/_next/static/chunks/7500-ac903ac440d9bd0c.js41 KB33 KB (86%)✓3rd
https://duckduckgo.com/_next/static/chunks/9489-163017072c02f8f7.js55 KB33 KB (62%)✓3rd
https://duckduckgo.com/_next/static/chunks/pages/_app-ab8d89ae7e89fc12.js94 KB27 KB (29%)✓3rd
https://duckduckgo.com/_next/static/chunks/1471-a5f2e22b7a565394.js61 KB26 KB (45%)✓3rd
https://duckduckgo.com/_next/static/chunks/7317-fc8a2b4e02577123.js50 KB25 KB (52%)✓3rd
https://duckduckgo.com/_next/static/chunks/framework-676ac3c731e183b1.js61 KB21 KB (35%)✓3rd
https://duckduckgo.com/_next/static/chunks/3748-40dd748d82c081b6.js9 KB—✓3rd
https://duckduckgo.com/_next/static/chunks/6848-990672857ed33ce8.js6 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

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 (218 KB)
PASS
5 fonts (218 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

5

218 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 FCP 2.3 s LCP 4.8 shttps://duckduckgo.com/static-assets/font/ProximaNova-RegIt-webfont.woff2ProximaNova-RegIt-webfo... https://duckduckgo.com/static-assets/font/ProximaNova-RegIt-webfont.woff2 — 43.8 KiB — 0 ms — font-display: swaphttps://duckduckgo.com/static-assets/font/ProximaNova-Reg-webfont.woff2ProximaNova-Reg-webfont... https://duckduckgo.com/static-assets/font/ProximaNova-Reg-webfont.woff2 — 43.2 KiB — 0 ms — font-display: swaphttps://duckduckgo.com/static-assets/font/ProximaNova-Sbold-webfont.woff2ProximaNova-Sbold-webfo... https://duckduckgo.com/static-assets/font/ProximaNova-Sbold-webfont.woff2 — 43.1 KiB — 0 ms — font-display: swaphttps://duckduckgo.com/static-assets/font/ProximaNova-Bold-webfont.woff2ProximaNova-Bold-webfon... https://duckduckgo.com/static-assets/font/ProximaNova-Bold-webfont.woff2 — 43.7 KiB — 0 ms — font-display: swaphttps://duckduckgo.com/static-assets/font/ProximaNova-ExtraBold-webfont.woff2ProximaNova-ExtraBold-w... https://duckduckgo.com/static-assets/font/ProximaNova-ExtraBold-webfont.woff2 — 44.0 KiB — 0 ms — font-display: swap
ProximaNova-RegIt-webfo... woff2 swap
Size 44 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
ProximaNova-Reg-webfont... woff2 swap
Size 43 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
ProximaNova-Sbold-webfo... woff2 swap
Size 43 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
ProximaNova-Bold-webfon... woff2 swap
Size 44 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
ProximaNova-ExtraBold-w... woff2 swap
Size 44 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
27 hints, 0 missing preconnects
PASS
27 hints, 0 missing preconnects
Info::
Page uses 27 resource hint(s)

Current Resource Hints

preconnect
1
preload
+16
26
dns-prefetch
—
prefetch
—

27 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
A
HTTP Caching
max-age=31536000 (52 weeks)
PASS
max-age=31536000 (52 weeks)
Info::
Cache-Control header is set
Got: max-age=31536000
Info::
Effective TTL: 52 weeks (max-age=31536000)
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

max-age=31536000

DirectiveValueMeaning
max-age31536000Cache for 52 weeks
Effective TTL: 31536000 seconds
Network Waterfall
105 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
100% of JavaScript execution is third-party
First-party Third-party 3975ms · 277KB · $53/mo
duckduckgo.com
Other
Costly
Execution 2187ms
Transfer 61 KB
Unused 35%
Monthly Cost $29/mo
Unattributable
Other
Costly
Execution 582ms
Transfer 0 KB
Monthly Cost $8/mo
duckduckgo.com
Other
Costly
Execution 357ms
Transfer 42 KB
Monthly Cost $5/mo
duckduckgo.com
Other
Costly
Execution 309ms
Transfer 3 KB
Monthly Cost $4/mo
duckduckgo.com
Other
Costly
Execution 271ms
Transfer 94 KB
Unused 29%
Monthly Cost $4/mo
duckduckgo.com
Other
Optional
Execution 180ms
Transfer 38 KB
Monthly Cost $2/mo
duckduckgo.com
Other
Optional
Execution 89ms
Transfer 39 KB
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • duckduckgo.com adds 2187ms and costs ~$29/month
  • Unattributable adds 582ms and costs ~$8/month
  • duckduckgo.com adds 357ms and costs ~$5/month
  • duckduckgo.com adds 309ms and costs ~$4/month
  • duckduckgo.com adds 271ms 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

duckduckgo.com takes 2187ms 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 582ms 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

duckduckgo.com takes 357ms 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

duckduckgo.com takes 309ms 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

duckduckgo.com takes 271ms 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

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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