Performance
· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
2.80 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
34.11 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
3.76 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.035
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
9.31 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.
35.59 s
Page Load Progression
FPage Weight BudgetAction5.8 MB transferred, 156 requestsFIX
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.
Source: web.dev
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.
Source: web.dev
Subset fonts to include only used characters, or switch to system font stacks.
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.
High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.
Source: web.dev
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction12229ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.vox.com/_next/static/chunks/pages/_app-3159785359f717d1.js | 2469ms | 1965ms | 239ms | 3rd |
| Unattributable | 1833ms | 440ms | 0ms | 3rd |
| https://www.vox.com/ | 1499ms | 17ms | 1ms | 3rd |
| https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604200101/pubads_impl.js?cb=31097964 | 933ms | 831ms | 44ms | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202602.1.0/otTCF.js | 919ms | 827ms | 7ms | 3rd |
| https://www.vox.com/_next/static/chunks/framework-8e0f3cf51af7b1e2.js | 917ms | 859ms | 15ms | 3rd |
| https://cdn.concert.io/lib/concert-ads/v2-latest/concert_ads.js | 899ms | 701ms | 43ms | 3rd |
| https://www.vox.com/metrics/gtm.js?id=GTM-WQ5FM5W | 448ms | 336ms | 82ms | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202602.1.0/otBannerSdk.js | 442ms | 290ms | 45ms | 3rd |
| https://www.vox.com/metrics/?id=G-C3QZPB4GVE&cx=c>m=4e64h1 | 321ms | 277ms | 42ms | 3rd |
Showing top 10 of 22 scripts
FJS BundlesAction43 scripts, 1.3 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.vox.com/metrics/gtm.js?id=GTM-WQ5FM5W | 698 KB | 213 KB (31%) | ✓ | 3rd |
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 0 KB | 177 KB (49%) | ✓ | 3rd |
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 362 KB | 177 KB (49%) | ✓ | 3rd |
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 362 KB | 177 KB (49%) | ✓ | 3rd |
| https://www.vox.com/_next/static/chunks/pages/_app-3159785359f717d1.js | 443 KB | 172 KB (39%) | ✓ | 3rd |
| https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604200101/pubads_impl.js?cb=31097964 | 188 KB | 131 KB (70%) | ✓ | 3rd |
| https://www.vox.com/metrics/gtd?id=AW-926030959&cx=c>m=4e64h1 | 144 KB | 72 KB (50%) | ✓ | 3rd |
| https://www.vox.com/metrics/?id=G-C3QZPB4GVE&cx=c>m=4e64h1 | 156 KB | 65 KB (42%) | ✓ | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202602.1.0/otBannerSdk.js | 129 KB | 60 KB (47%) | ✓ | 3rd |
| https://c.amazon-adsystem.com/aax2/apstag.js | 91 KB | 38 KB (42%) | ✓ | 3rd |
Consider code splitting or tree shaking to reduce unused code.
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.
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.
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.
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.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
FPage Weight InventoryAction156 resources · 5.8 MB · 1.3 MB savings availableFIX
~1.3 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 156 resources | 5.8 MiB | ||||||
BImage Optimization32 images, 0 KB saveableREVIEW
Set explicit width and height to prevent CLS.
Performance issues directly impact user engagement and conversion rates.
A+Text CompressionAll text resources are compressedPASS
A+Font Loading11 fonts (448 KB)PASS
Web fonts
11
448 KB total
Render-blocking
0
of 11
Dominant font-display
swap
Most common across fonts
Font loading timeline
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 CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource Hints23 hints, 0 missing preconnectsPASS
Current Resource Hints
23 resource hints configured
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Axis12 Ltd
AHTTP Cachingmax-age=86400 (1 day)PASS
max-age=86400
| Directive | Value | Meaning |
|---|---|---|
| max-age | 86400 | Cache for 1 day |
Network Waterfall156 requests over 10723msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.vox.com www.vox.com | Other | 2469ms | 443 KB | 39% | $33/mo | Costly |
Unattributable Unattributable | Other | 1833ms | 0 KB | — | $24/mo | Costly |
www.vox.com www.vox.com | Other | 1499ms | 40 KB | — | $20/mo | Costly |
securepubads.g.doubleclick.net securepubads.g.doubleclick.net | Other | 933ms | 188 KB | 70% | $12/mo | Costly |
OneTrust cdn.cookielaw.org | Consent | 919ms | 18 KB | — | $12/mo | Essential |
www.vox.com www.vox.com | Other | 917ms | 42 KB | — | $12/mo | Costly |
cdn.concert.io cdn.concert.io | Other | 899ms | 104 KB | 51% | $12/mo | Costly |
www.vox.com www.vox.com | Other | 448ms | 698 KB | 31% | $6/mo | Costly |
OneTrust cdn.cookielaw.org | Consent | 442ms | 129 KB | 47% | $6/mo | Essential |
www.vox.com www.vox.com | Other | 321ms | 156 KB | 42% | $4/mo | Costly |
c.amazon-adsystem.com c.amazon-adsystem.com | Other | 285ms | 91 KB | 42% | $4/mo | Costly |
www.gstatic.com www.gstatic.com | Other | 234ms | 0 KB | 49% | $3/mo | Costly |
www.vox.com www.vox.com | Other | 224ms | 144 KB | 50% | $3/mo | Costly |
btloader.com btloader.com | Other | 186ms | 37 KB | — | $2/mo | Optional |
pub.doubleverify.com pub.doubleverify.com | Other | 126ms | 34 KB | — | $2/mo | Optional |
www.vox.com www.vox.com | Other | 89ms | 31 KB | — | $1/mo | Optional |
luminousboulevard.com luminousboulevard.com | Other | 88ms | 38 KB | — | $1/mo | Optional |
www.googletagservices.com www.googletagservices.com | Other | 80ms | 34 KB | — | $1/mo | Optional |
www.vox.com www.vox.com | Other | 64ms | 18 KB | — | $1/mo | Optional |
config.aps.amazon-adsystem.com config.aps.amazon-adsystem.com | Other | 61ms | 4 KB | — | $1/mo | Optional |
sb.scorecardresearch.com sb.scorecardresearch.com | Other | 59ms | 0 KB | — | $1/mo | Optional |
secure.cdn.fastclick.net secure.cdn.fastclick.net | Other | 53ms | 22 KB | — | $1/mo | Optional |
These scripts may cost more than they're worth
- www.vox.com adds 2469ms and costs ~$33/month
- Unattributable adds 1833ms and costs ~$24/month
- www.vox.com adds 1499ms and costs ~$20/month
- securepubads.g.doubleclick.net adds 933ms and costs ~$12/month
- www.vox.com adds 917ms and costs ~$12/month
- cdn.concert.io adds 899ms and costs ~$12/month
- www.vox.com adds 448ms and costs ~$6/month
- www.vox.com adds 321ms and costs ~$4/month
- c.amazon-adsystem.com adds 285ms and costs ~$4/month
- www.gstatic.com adds 234ms and costs ~$3/month
- www.vox.com adds 224ms and costs ~$3/month
100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.
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
www.vox.com takes 2469ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
Unattributable takes 1833ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.vox.com takes 1499ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
securepubads.g.doubleclick.net takes 933ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
70% of securepubads.g.doubleclick.net's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
www.vox.com takes 917ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
cdn.concert.io takes 899ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
51% of cdn.concert.io's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
www.vox.com takes 448ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.vox.com takes 321ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
c.amazon-adsystem.com takes 285ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.gstatic.com takes 234ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.vox.com takes 224ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
50% of www.vox.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev