Skip to content
https://www.dropbox.com

Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
72
GRADE
C
FIX
5
REVIEW
2
PASS
7
INFO
2

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

Mobile Desktop
38
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.
77
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.

2.87 s

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

5.64 s

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

3.31 s

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

0.053

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

6.63 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.

21.03 s

Page Load Progression

909 ms
1.8 s
2.7 s
3.6 s
4.5 s
5.5 s
6.4 s
7.3 s
Checks
16
7 PASS 2 REVIEW 5 FIX
F
Page Weight Budget
Action
11.4 MB transferred, 570 requests
FIX
11.4 MB transferred, 570 requests
Critical::
Page weighs 18.0 MB (11.4 MB transferred)
Warning::
JavaScript is 2.3 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 2.3 MB
Info::
Fonts are 411 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 411 KB
Warning::
570 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 2.4 g CO2 per page load
11.4 MB / 2.4 MB budget
11.4 MB transferred
570 requests
2.4 g CO2 per page load
Other 8.3 MiB 72%
JavaScript 2.3 MiB 20%
Fonts 410.9 KiB 4%
CSS 191.6 KiB 2%
HTML 114.5 KiB 1%
Images 100.6 KiB 1%
Other 10.3 KiB 0%
Other 1.5 KiB 0%
Other 1.1 KiB 0%
Other 353 B 0%
0 2.4 MB 4.9 MB
Over 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

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
99% third-party, 0 ms blocking
FIX
99% third-party, 0 ms blocking
Warning::
Third-party code accounts for 99% of page weight (11.2 MiB of 11.4 MiB)
Info::
Third-party blocking time is low (0 ms)
99%
First-party Third-party
F
JS Execution Cost
Action
13623ms total JS execution
FIX
13623ms total JS execution
Warning::
https://cfl.dropboxstatic.com/static/atlas/warp/wa...: 3415ms CPU time
Warning::
Unattributable: 3101ms CPU time
Warning::
https://www.dropbox.com/: 1549ms CPU time
Warning::
https://cfl.dropboxstatic.com/static/metaserver/st...: 1422ms CPU time
Warning::
https://cfl.dropboxstatic.com/static/atlas/warp/wa...: 1395ms CPU time
Warning::
Third-party scripts: 11940ms (88% of total)

Main Thread Breakdown

Script Evaluation 47% Other 29% Style & Layout 11% Script Parsing & Compilation 8%
ScriptTotalScriptingParse/CompileParty
https://cfl.dropboxstatic.com/static/atlas/warp/warp_page_edison_bundle_amd/dist/e_warp_warp_page_edison-vflpSArJJ.js3415ms1826ms292ms3rd
Unattributable3101ms109ms0ms3rd
https://www.dropbox.com/1549ms124ms41ms1st
https://cfl.dropboxstatic.com/static/metaserver/static/js/alameda_bundle/alameda_bundle_chrome_en-vflMwBej6.js1422ms1349ms34ms3rd
https://cfl.dropboxstatic.com/static/atlas/warp/warp_page_edison_bundle_amd/dist/c_fingerprintjs_fpjs-pro-static_fp-vflGINDbV.js1395ms1088ms26ms3rd
https://cfl.dropboxstatic.com/static/atlas/warp/warp_page_edison_bundle_amd/dist/c_contentsquare-vflDuiebi.js324ms263ms57ms3rd
https://cfl.dropboxstatic.com/static/atlas/privacy_consent/ccpa_iframe_bundle_amd/dist/e_privacy_consent_static_ccpa_iframe-vflzWfccK.js273ms36ms92ms3rd
https://cfl.dropboxstatic.com/static/atlas/warp/warp_page_edison_bundle_amd/dist/c_redux_namespaces-vfllYdCgN.js267ms226ms2ms3rd
https://cfl.dropboxstatic.com/static/atlas/warp/warp_page_edison_bundle_amd/dist/c_src_sink_index-vflvP-sUe.js238ms143ms10ms3rd
https://cfl.dropboxstatic.com/static/atlas/warp/warp_page_edison_bundle_amd/dist/e_react-dom-vflxkx0XF.js210ms181ms19ms3rd

Showing top 10 of 22 scripts

F
JS Bundles
Action
420 scripts, 741 KB unused
FIX
420 scripts, 741 KB unused
Warning::
https://cfl.dropboxstatic.com/static/atlas/warp/wa...: 271 KB unused (52%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cfl.dropboxstatic.com/static/atlas/warp/wa...: 99 KB unused (90%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cfl.dropboxstatic.com/static/atlas/warp/wa...: 87 KB unused (62%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cfl.dropboxstatic.com/static/atlas/privacy...: 81 KB unused (44%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://accounts.google.com/gsi/client: 69 KB unused (75%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 741 KB
741 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://cfl.dropboxstatic.com/static/atlas/warp/warp_page_edison_bundle_amd/dist/e_warp_warp_page_edison-vflpSArJJ.js522 KB271 KB (52%)✓3rd
https://cfl.dropboxstatic.com/static/atlas/warp/warp_page_edison_bundle_amd/dist/c_trial-cards_trial-comparison-card-vflujfrXM.js110 KB99 KB (90%)✓3rd
https://cfl.dropboxstatic.com/static/atlas/warp/warp_page_edison_bundle_amd/dist/c_contentsquare-vflDuiebi.js140 KB87 KB (62%)✓3rd
https://cfl.dropboxstatic.com/static/atlas/privacy_consent/ccpa_iframe_bundle_amd/dist/e_privacy_consent_static_ccpa_iframe-vflzWfccK.js186 KB81 KB (44%)✓3rd
https://accounts.google.com/gsi/client93 KB69 KB (75%)✓3rd
https://cfl.dropboxstatic.com/static/metaserver/static/pithos/zoom_chat_client.bundle-vflZr0O8y.js75 KB56 KB (75%)✓3rd
https://cfl.dropboxstatic.com/static/atlas/warp/warp_page_edison_bundle_amd/dist/c_fingerprintjs_fpjs-pro-static_fp-vflGINDbV.js82 KB28 KB (34%)✓3rd
https://cfl.dropboxstatic.com/static/atlas/privacy_consent/ccpa_iframe_bundle_amd/dist/e_core_exception_reporter-vflBUHcDZ.js34 KB25 KB (74%)✓3rd
https://cfl.dropboxstatic.com/static/atlas/warp/warp_page_edison_bundle_amd/dist/e_core_exception_reporter-vflkYePyQ.js34 KB25 KB (73%)✓3rd
https://cfl.dropboxstatic.com/static/atlas/warp/warp_page_edison_bundle_amd/dist/c_dig-icons_assets_ui-icon_external-logo_linux-vfljfH_Gi.js3 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

D
HTTP Caching
Action
no-store (uncacheable)
FIX
no-store (uncacheable)
Info::
Cache-Control: no-store prevents all caching
Intentional for dynamic content, but increases server load for every page view.
Got: no-cache, no-store
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

no-cache, no-store

DirectiveValueMeaning
no-cache—Cache but always revalidate first
no-store—Never cache this response
B
Image Optimization
17 images, 0 KB saveable
REVIEW
17 images, 0 KB saveable
Info::
All images are well-optimized
17 images 101 KB
0 oversized -0 KB
15 legacy format
0 missing dimensions CLS risk
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
8 fonts (411 KB)
PASS
8 fonts (411 KB)
Info::
8 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

8

411 KB total

Render-blocking

0

of 8

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 2.9 s LCP 5.6 shttps://cfl.dropboxstatic.com/static/metaserver/static/fonts/dig-fonts/atlas_grotesk/AtlasGrotesk-Medium-Web-vfl38XiTL.woff2AtlasGrotesk-Medium-Web... https://cfl.dropboxstatic.com/static/metaserver/static/fonts/dig-fonts/atlas_grotesk/AtlasGrotesk-Medium-Web-vfl38XiTL.woff2 — 45.3 KiB — 0 ms — font-display: swaphttps://cfl.dropboxstatic.com/static/metaserver/static/fonts/dig-fonts/atlas_grotesk/AtlasGrotesk-Regular-Web-vflk7bxjs.woff2AtlasGrotesk-Regular-We... https://cfl.dropboxstatic.com/static/metaserver/static/fonts/dig-fonts/atlas_grotesk/AtlasGrotesk-Regular-Web-vflk7bxjs.woff2 — 42.5 KiB — 0 ms — font-display: swaphttps://cfl.dropboxstatic.com/static/metaserver/static/fonts/dig-fonts/sharp_grotesk/SharpGroteskDBCyrBook20-vfl6-4ZSp.woff2SharpGroteskDBCyrBook20... https://cfl.dropboxstatic.com/static/metaserver/static/fonts/dig-fonts/sharp_grotesk/SharpGroteskDBCyrBook20-vfl6-4ZSp.woff2 — 53.5 KiB — 0 ms — font-display: swaphttps://cfl.dropboxstatic.com/static/metaserver/static/fonts/dig-fonts/sharp_grotesk/SharpGroteskDBCyrMedium20-vflI3qtaE.woff2SharpGroteskDBCyrMedium... https://cfl.dropboxstatic.com/static/metaserver/static/fonts/dig-fonts/sharp_grotesk/SharpGroteskDBCyrMedium20-vflI3qtaE.woff2 — 54.1 KiB — 0 ms — font-display: swaphttps://cfl.dropboxstatic.com/static/metaserver/static/fonts/dig-fonts/sharp_grotesk_23/SharpGroteskDBCyrBook23-vflX-NIwB.woff2SharpGroteskDBCyrBook23... https://cfl.dropboxstatic.com/static/metaserver/static/fonts/dig-fonts/sharp_grotesk_23/SharpGroteskDBCyrBook23-vflX-NIwB.woff2 — 58.3 KiB — 0 ms — font-display: swaphttps://cfl.dropboxstatic.com/static/metaserver/static/fonts/sharpgrotesk/SharpGroteskDBMedium22-vflJ24ZPh.woff2SharpGroteskDBMedium22-... https://cfl.dropboxstatic.com/static/metaserver/static/fonts/sharpgrotesk/SharpGroteskDBMedium22-vflJ24ZPh.woff2 — 60.5 KiB — 0 ms — font-display: swaphttps://cfl.dropboxstatic.com/static/metaserver/static/fonts/paper-atlasgrotesk/AtlasGrotesk-Regular-Web-vflk7bxjs.woff2AtlasGrotesk-Regular-We... https://cfl.dropboxstatic.com/static/metaserver/static/fonts/paper-atlasgrotesk/AtlasGrotesk-Regular-Web-vflk7bxjs.woff2 — 42.6 KiB — 0 ms — font-display: swaphttps://cfl.dropboxstatic.com/static/metaserver/static/fonts/sharpgrotesk/SharpGroteskDBMedium20-vflI3qtaE.woff2SharpGroteskDBMedium20-... https://cfl.dropboxstatic.com/static/metaserver/static/fonts/sharpgrotesk/SharpGroteskDBMedium20-vflI3qtaE.woff2 — 54.2 KiB — 0 ms — font-display: swap
AtlasGrotesk-Medium-Web... woff2 swap
Size 45 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
AtlasGrotesk-Regular-We... woff2 swap
Size 42 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
SharpGroteskDBCyrBook20... woff2 swap
Size 54 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
SharpGroteskDBCyrMedium... woff2 swap
Size 54 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
SharpGroteskDBCyrBook23... woff2 swap
Size 58 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
SharpGroteskDBMedium22-... woff2 swap
Size 60 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
AtlasGrotesk-Regular-We... woff2 swap
Size 43 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
SharpGroteskDBMedium20-... woff2 swap
Size 54 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
7 hints, 0 missing preconnects
PASS
7 hints, 0 missing preconnects
Info::
Page uses 7 resource hint(s)

Current Resource Hints

preconnect
—
preload
7
dns-prefetch
—
prefetch
—

7 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
Network Waterfall
570 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
88% of JavaScript execution is third-party
First-party Third-party 11940ms · 1330KB · $224/mo
cfl.dropboxstatic.com
Other
Costly
Execution 3415ms
Transfer 522 KB
Unused 52%
Monthly Cost $64/mo
Unattributable
Other
Costly
Execution 3101ms
Transfer 0 KB
Monthly Cost $58/mo
cfl.dropboxstatic.com
Other
Costly
Execution 1422ms
Transfer 0 KB
Monthly Cost $27/mo
cfl.dropboxstatic.com
Other
Costly
Execution 1395ms
Transfer 82 KB
Unused 34%
Monthly Cost $26/mo
cfl.dropboxstatic.com
Other
Costly
Execution 324ms
Transfer 140 KB
Unused 62%
Monthly Cost $6/mo
cfl.dropboxstatic.com
Other
Costly
Execution 273ms
Transfer 186 KB
Unused 44%
Monthly Cost $5/mo
cfl.dropboxstatic.com
Other
Costly
Execution 267ms
Transfer 4 KB
Monthly Cost $5/mo
cfl.dropboxstatic.com
Other
Costly
Execution 238ms
Transfer 16 KB
Monthly Cost $4/mo
cfl.dropboxstatic.com
Other
Costly
Execution 210ms
Transfer 47 KB
Monthly Cost $4/mo
cfl.dropboxstatic.com
Other
Optional
Execution 197ms
Transfer 20 KB
Monthly Cost $4/mo
cfl.dropboxstatic.com
Other
Optional
Execution 166ms
Transfer 47 KB
Monthly Cost $3/mo
cfl.dropboxstatic.com
Other
Optional
Execution 155ms
Transfer 21 KB
Monthly Cost $3/mo
cfl.dropboxstatic.com
Other
Optional
Execution 136ms
Transfer 17 KB
Monthly Cost $3/mo
cfl.dropboxstatic.com
Other
Optional
Execution 130ms
Transfer 11 KB
Monthly Cost $2/mo
cfl.dropboxstatic.com
Other
Optional
Execution 130ms
Transfer 11 KB
Monthly Cost $2/mo
accounts.google.com
Other
Optional
Execution 119ms
Transfer 93 KB
Unused 75%
Monthly Cost $2/mo
cfl.dropboxstatic.com
Other
Optional
Execution 72ms
Transfer 10 KB
Monthly Cost $1/mo
cfl.dropboxstatic.com
Other
Optional
Execution 68ms
Transfer 16 KB
Monthly Cost $1/mo
cfl.dropboxstatic.com
Other
Optional
Execution 61ms
Transfer 75 KB
Unused 75%
Monthly Cost $1/mo
cfl.dropboxstatic.com
Other
Optional
Execution 61ms
Transfer 11 KB
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • cfl.dropboxstatic.com adds 3415ms and costs ~$64/month
  • Unattributable adds 3101ms and costs ~$58/month
  • cfl.dropboxstatic.com adds 1422ms and costs ~$27/month
  • cfl.dropboxstatic.com adds 1395ms and costs ~$26/month
  • cfl.dropboxstatic.com adds 324ms and costs ~$6/month
  • cfl.dropboxstatic.com adds 273ms and costs ~$5/month
  • cfl.dropboxstatic.com adds 267ms and costs ~$5/month
  • cfl.dropboxstatic.com adds 238ms and costs ~$4/month
  • cfl.dropboxstatic.com adds 210ms and costs ~$4/month

88% 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

cfl.dropboxstatic.com takes 3415ms 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

52% of cfl.dropboxstatic.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

Unattributable takes 3101ms 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

cfl.dropboxstatic.com takes 1422ms 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

cfl.dropboxstatic.com takes 1395ms 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

cfl.dropboxstatic.com takes 324ms 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

62% of cfl.dropboxstatic.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

cfl.dropboxstatic.com takes 273ms 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

cfl.dropboxstatic.com takes 267ms 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

cfl.dropboxstatic.com takes 238ms 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

cfl.dropboxstatic.com takes 210ms 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

75% of accounts.google.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

75% of cfl.dropboxstatic.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.

Send Feedback