Performance
· 15 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.
865 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.66 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
94 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.040
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.60 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.
3.75 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 sFPage Weight BudgetAction4.9 MB transferred, 216 requestsFIX
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
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
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 BundlesAction143 scripts, 676 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.jstor.org/assets/global_20251201T215504/build/global/js/global.min.js | 137 KB | 106 KB (78%) | ✓ | 3rd |
| https://www.jstor.org/mfe-copper-roof/header/0becc8f3/ithaka-sentry-monitoring_2_5_1.1f659a8c1c0e6710c4fb.js | 113 KB | 97 KB (86%) | ✓ | 3rd |
| https://www.jstor.org/mfe-copper-roof/query-builder/0b448bab/ithaka-sentry-monitoring_2_5_0.0d496c87e6b939e77a01.js | 109 KB | 96 KB (88%) | ✓ | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202505.1.0/otBannerSdk.js | 119 KB | 62 KB (53%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-N6GDC22 | 180 KB | 51 KB (28%) | ✓ | 3rd |
| https://www.jstor.org/mfe-copper-roof/access-workflow/8e13cdaf/vueuse-core_14_1_0.386260f905cc509f4c09.js | 46 KB | 42 KB (93%) | ✓ | 3rd |
| https://www.jstor.org/mfe-copper-roof/header/0becc8f3/graphql_16_12_0.ad3ea3a551ab737d4361.js | 42 KB | 33 KB (78%) | ✓ | 3rd |
| https://www.jstor.org/mfe-copper-roof/header/0becc8f3/css-loader_7_1_4.8628ef76acff23726230.js | 56 KB | 29 KB (51%) | ✓ | 3rd |
| https://www.jstor.org/mfe-copper-roof/provider-designation-statement/f3b07e9a/css-loader_7_1_2.559c8411029e2e7dfe20.js | 46 KB | 24 KB (54%) | ✓ | 3rd |
| https://www.jstor.org/mfe-copper-roof/footer/68fef919/vue_3_5_26.dabfd7ee9635f42e057b.js | 44 KB | 24 KB (54%) | ✓ | 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 InventoryAction216 resources · 4.9 MB · 676 KB savings availableFIX
~676.1 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 216 resources | 4.9 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction32 images, 0 KB saveableREVIEW
Set explicit width and height to prevent CLS.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
CJS Execution CostAction1113ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 290ms | 37ms | 0ms | 3rd |
| https://www.jstor.org/ | 214ms | 4ms | 1ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-N6GDC22 | 196ms | 172ms | 22ms | 3rd |
| https://www.jstor.org/mfe-copper-roof/header/0becc8f3/react-dom_19_2_4.57e05c9d2ee42bf1ac13.js | 159ms | 144ms | 5ms | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202505.1.0/otBannerSdk.js | 81ms | 54ms | 14ms | 3rd |
| https://www.jstor.org/assets/search-ui_20250818T182451/build/2443.js | 63ms | 54ms | 6ms | 3rd |
| https://www.jstor.org/assets/long-lived_20201006/js/scoped-custom-element-registry@0.0.3.min.js | 56ms | 49ms | 0ms | 3rd |
| https://www.jstor.org/mfe-copper-roof/footer/68fef919/src_initComponents_ts.d1a6325fb7fd2b2d7ff1.js | 54ms | 46ms | 0ms | 3rd |
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
A+Font Loading8 fonts (375 KB)PASS
Web fonts
8
375 KB total
Render-blocking
0
of 8
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
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)
Fixing the unchecked items could save ~73 KB and ~146 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall216 requests over 1980msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 290ms | 0 KB | — | $4/mo | Costly |
www.jstor.org www.jstor.org | Other | 214ms | 9 KB | — | $3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 196ms | 180 KB | 28% | $3/mo | Optional |
www.jstor.org www.jstor.org | Other | 159ms | 56 KB | 42% | $2/mo | Optional |
OneTrust cdn.cookielaw.org | Consent | 81ms | 119 KB | 53% | $1/mo | Essential |
www.jstor.org www.jstor.org | Other | 63ms | 54 KB | 39% | $1/mo | Optional |
www.jstor.org www.jstor.org | Other | 56ms | 2 KB | — | $1/mo | Optional |
www.jstor.org www.jstor.org | Other | 54ms | 1 KB | — | $1/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 290ms and costs ~$4/month
- www.jstor.org adds 214ms 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
Unattributable takes 290ms 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.jstor.org takes 214ms 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
53% of OneTrust'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