Performance
· 22 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.
989 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
2.24 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
376 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.010
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
2.96 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.
33.45 s
Page Load Progression
FPage Weight BudgetAction65.3 MB transferred, 178 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
DJS Execution CostAction3206ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.vox.com/_next/static/chunks/pages/_app-30a59684a390f47a.js | 931ms | 703ms | 60ms | 3rd |
| Unattributable | 628ms | 38ms | 0ms | 1st |
| https://www.vox.com/_next/static/chunks/framework-0d38badde70e1eb1.js | 552ms | 428ms | 7ms | 3rd |
| https://www.vox.com/ | 317ms | 3ms | 0ms | 3rd |
| https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202608070101/pubads_impl.js | 199ms | 159ms | 10ms | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202602.1.0/otTCF.js | 187ms | 168ms | 1ms | 3rd |
| https://cdn.concert.io/lib/concert-ads/v2-latest/concert_ads.js | 159ms | 134ms | 7ms | 3rd |
| https://www.vox.com/metrics/gtm.js?id=GTM-WQ5FM5W | 95ms | 80ms | 13ms | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202602.1.0/otBannerSdk.js | 81ms | 51ms | 10ms | 3rd |
| https://www.vox.com/metrics/X2pNAxh7A7o0j2QYEgg8C8whl2jOXxLiGUNUm9xVUTBWWBITTGwE | 57ms | 49ms | 8ms | 3rd |
FJS BundlesAction48 scripts, 1.6 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.vox.com/_next/static/chunks/pages/_app-30a59684a390f47a.js | 508 KB | 223 KB (44%) | ✓ | 3rd |
| https://www.vox.com/metrics/gtm.js?id=GTM-WQ5FM5W | 721 KB | 219 KB (30%) | ✓ | 3rd |
| https://www.gstatic.com/recaptcha/releases/XOqlk8PL_yVx6IdpLbpXdiLy/recaptcha__en.js | 336 KB | 181 KB (54%) | ✓ | 3rd |
| https://www.gstatic.com/recaptcha/releases/XOqlk8PL_yVx6IdpLbpXdiLy/recaptcha__en.js | 336 KB | 181 KB (54%) | ✓ | 3rd |
| https://www.gstatic.com/recaptcha/releases/XOqlk8PL_yVx6IdpLbpXdiLy/recaptcha__en.js | 0 KB | 181 KB (54%) | ✓ | 3rd |
| https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202608070101/pubads_impl.js | 201 KB | 140 KB (70%) | ✓ | 3rd |
| https://www.vox.com/_next/static/chunks/1bdf6b2c-892d5a67e11b79d1.js | 140 KB | 77 KB (56%) | ✓ | 3rd |
| https://www.vox.com/metrics/X2pNAxh7A7o0iR52GGtQa70l6QuyXxLiGUNUm9xVUTBWWBITTGwE | 150 KB | 75 KB (50%) | ✓ | 3rd |
| https://www.vox.com/metrics/X2pNAxh7A7o0j2QYEgg8C8whl2jOXxLiGUNUm9xVUTBWWBITTGwE | 163 KB | 70 KB (43%) | ✓ | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202602.1.0/otBannerSdk.js | 129 KB | 60 KB (47%) | ✓ | 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 InventoryAction178 resources · 65.3 MB · 1.6 MB savings availableFIX
~1.6 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 178 resources | 65.3 MiB | ||||||
BImage Optimization32 images, 0 KB saveableREVIEW
BHTTP/3 (QUIC)HTTP/3 not advertisedREVIEW
CCompression AlgorithmActionMain response served uncompressedREVIEW
CMain HTML Cache-ControlActionMain HTML max-age=86400 (~1440min) is aggressiveREVIEW
BServer-Timing ObservabilityNo Server-Timing header foundREVIEW
A+Text CompressionAll text resources are compressedPASS
A+Font Loading11 fonts (447 KB)PASS
Web fonts
11
447 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 HintsNo optimization neededPASS
A+LCP Image PreloadLCP preload audit not availablePASS
A+Server Response Intelligence1 server-response signal(s) 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 Waterfall178 requests over 41376msINFO
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 | 931ms | 508 KB | 44% | $12/mo | Costly |
www.vox.com www.vox.com | Other | 552ms | 42 KB | — | $7/mo | Costly |
www.vox.com www.vox.com | Other | 317ms | 39 KB | — | $4/mo | Costly |
securepubads.g.doubleclick.net securepubads.g.doubleclick.net | Other | 199ms | 201 KB | 70% | $3/mo | Optional |
OneTrust cdn.cookielaw.org | Consent | 187ms | 18 KB | — | $2/mo | Essential |
cdn.concert.io cdn.concert.io | Other | 159ms | 104 KB | 52% | $2/mo | Optional |
www.vox.com www.vox.com | Other | 95ms | 721 KB | 30% | $1/mo | Optional |
OneTrust cdn.cookielaw.org | Consent | 81ms | 129 KB | 47% | $1/mo | Essential |
www.vox.com www.vox.com | Other | 57ms | 163 KB | 43% | $1/mo | Optional |
These scripts may cost more than they're worth
- www.vox.com adds 931ms and costs ~$12/month
- www.vox.com adds 552ms and costs ~$7/month
- www.vox.com adds 317ms and costs ~$4/month
80% 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 931ms 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 552ms 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 317ms 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
52% 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
Image Optimization137 images, 0 KB total, 0 KB wastedINFO
Image Optimization Audit
Total Images
137
Total Size
0 KB