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Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
80
GRADE
B
FIX
3
REVIEW
2
PASS
7
INFO
2

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

Mobile Desktop
93
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
96
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.

787 ms

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

1.11 s

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

168 ms

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.

1.22 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.

1.99 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
7 PASS 2 REVIEW 3 FIX
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 (1.9 MiB of 1.9 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
D
JS Bundles
Action
31 scripts, 409 KB unused
FIX
31 scripts, 409 KB unused
Warning::
https://cdn.ketchjs.com/ketchtag/stable/v2.12/ketc...: 117 KB unused (46%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://bitwarden.com/build/assets/footer-DukkO7QU...: 101 KB unused (64%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-NF3...: 80 KB unused (44%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://bitwarden.com/build/assets/app-DDjafNz8.js: 50 KB unused (47%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://bitwarden.com/build/assets/landing-page-CU...: 41 KB unused (54%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 409 KB
409 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://cdn.ketchjs.com/ketchtag/stable/v2.12/ketch-sdk.js257 KB117 KB (46%)✓3rd
https://bitwarden.com/build/assets/footer-DukkO7QU.js158 KB101 KB (64%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-NF32QCS180 KB80 KB (44%)✓3rd
https://bitwarden.com/build/assets/app-DDjafNz8.js105 KB50 KB (47%)✓3rd
https://bitwarden.com/build/assets/landing-page-CUBxvOJk.js77 KB41 KB (54%)✓3rd
https://bitwarden.com/build/assets/page-wrapper-CuWZ0L4E.js55 KB20 KB (37%)✓3rd
https://bitwarden.com/build/assets/article-list-card-BcZts8nl.js2 KB—✓3rd
https://bitwarden.com/build/assets/text-field-NSAZYs4U.js1 KB—✓3rd
https://bitwarden.com/build/assets/print-GrKw0ow3.js0 KB—✓3rd
https://bitwarden.com/build/assets/shield-loader-9YvpToAp.js0 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

F
HTTP Caching
Action
No cache headers
FIX
No cache headers
Warning::
No Cache-Control header found
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.

C
Page Weight Budget
Action
1.9 MB transferred, 69 requests
REVIEW
1.9 MB transferred, 69 requests
Info::
Page weighs 7.1 MB (1.9 MB transferred)
Warning::
JavaScript is 1.2 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.2 MB
Info::
69 HTTP requests
Info::
Estimated 0.41 g CO2 per page load
1.9 MB / 2.4 MB budget
1.9 MB transferred
69 requests
0.41 g CO2 per page load
JavaScript 1.2 MiB 63%
Images 392.1 KiB 20%
Other 105.0 KiB 5%
HTML 103.9 KiB 5%
Fonts 84.5 KiB 4%
CSS 46.3 KiB 2%
Other 10.4 KiB 1%
Other 988 B 0%
Other 350 B 0%
Other 0 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

C
JS Execution Cost
Action
1787ms total JS execution
REVIEW
1787ms total JS execution
Warning::
https://bitwarden.com/: 624ms CPU time
Warning::
https://bitwarden.com/build/assets/app-DDjafNz8.js: 503ms CPU time
Warning::
Unattributable: 257ms CPU time
Info::
https://cdn.ketchjs.com/ketchtag/stable/v2.12/ketc...: 135ms CPU time
Info::
https://www.googletagmanager.com/gtm.js?id=GTM-NF3...: 118ms CPU time
Warning::
Third-party scripts: 1787ms (100% of total)

Main Thread Breakdown

Script Evaluation 39% Other 25% Style & Layout 21% Rendering 7% Script Parsing & Compilation 4%
ScriptTotalScriptingParse/CompileParty
https://bitwarden.com/624ms51ms0ms3rd
https://bitwarden.com/build/assets/app-DDjafNz8.js503ms379ms0ms3rd
Unattributable257ms56ms0ms3rd
https://cdn.ketchjs.com/ketchtag/stable/v2.12/ketch-sdk.js135ms93ms37ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-NF32QCS118ms93ms24ms3rd
https://bitwarden.com/plsbl/js/script.outbound-links.tagged-events.pageview-props.file-downloads.js83ms10ms0ms3rd
https://bitwarden.com/build/assets/footer-DukkO7QU.js67ms16ms1ms3rd
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+
Image Optimization
16 images, 0 KB saveable
PASS
16 images, 0 KB saveable
Info::
All images are well-optimized
16 images 392 KB
0 oversized -0 KB
1 legacy format
0 missing dimensions CLS risk
A+
Font Loading
2 fonts (85 KB)
PASS
2 fonts (85 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

85 KB total

Render-blocking

0

of 2

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s FCP 787 ms LCP 1.1 shttps://cdn.jsdelivr.net/fontsource/fonts/inter:vf@latest/latin-wght-normal.woff2latin-wght-normal.woff2 https://cdn.jsdelivr.net/fontsource/fonts/inter:vf@latest/latin-wght-normal.woff2 — 47.6 KiB — 0 ms — font-display: swaphttps://bitwarden.com/build/assets/bwi-font-C46BVSvQ.woff2bwi-font-C46BVSvQ.woff2 https://bitwarden.com/build/assets/bwi-font-C46BVSvQ.woff2 — 36.9 KiB — 0 ms — font-display: swap
latin-wght-normal.woff2 woff2 swap
Size 48 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
bwi-font-C46BVSvQ.woff2 woff2 swap
Size 37 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+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Network Waterfall
69 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 1787ms · 807KB · $24/mo
bitwarden.com
Other
Costly
Execution 624ms
Transfer 104 KB
Monthly Cost $8/mo
bitwarden.com
Other
Costly
Execution 503ms
Transfer 105 KB
Unused 47%
Monthly Cost $7/mo
Unattributable
Other
Costly
Execution 257ms
Transfer 0 KB
Monthly Cost $3/mo
cdn.ketchjs.com
Other
Optional
Execution 135ms
Transfer 257 KB
Unused 46%
Monthly Cost $2/mo
Google Tag Manager
Tag Manager
Optional
Execution 118ms
Transfer 180 KB
Unused 44%
Monthly Cost $2/mo
bitwarden.com
Other
Optional
Execution 83ms
Transfer 3 KB
Monthly Cost $1/mo
bitwarden.com
Other
Optional
Execution 67ms
Transfer 158 KB
Unused 64%
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • bitwarden.com adds 624ms and costs ~$8/month
  • bitwarden.com adds 503ms and costs ~$7/month
  • Unattributable adds 257ms and costs ~$3/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

bitwarden.com takes 624ms 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

bitwarden.com takes 503ms 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 257ms 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

64% of bitwarden.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

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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