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.
917 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
3.71 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
122 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.
1.64 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.
3.72 s
Page Load Progression
FPage Weight BudgetAction3.8 MB transferred, 84 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
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
DJS BundlesAction37 scripts, 251 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://cdn.ketchjs.com/ketchtag/stable/v2.12/ketch-sdk.js | 259 KB | 164 KB (63%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-PK7T4JG | 164 KB | 87 KB (53%) | ✓ | 3rd |
| https://static.crunchyroll.com/cr-acquisition/index-19f9d112.141ba52bf0cf289251b2.js | 14 KB | — | ✗ | 3rd |
| https://static.crunchyroll.com/cr-acquisition/index-a5ce148e.c0456db481c305ddb14e.js | 5 KB | — | ✓ | 3rd |
| https://static.crunchyroll.com/cr-acquisition/index-51db7292.ad5843f9193a8596254c.js | 15 KB | — | ✓ | 3rd |
| https://static.crunchyroll.com/cr-acquisition/index-9a8b795a.3ee0b69b049182bd3e30.js | 9 KB | — | ✓ | 3rd |
| https://static.crunchyroll.com/cr-acquisition/index-cd271a2f.f5ac859306b0f48c4d78.js | 6 KB | — | ✓ | 3rd |
| https://static.crunchyroll.com/cr-acquisition/index-7f854005.793e3f1381f8a5edd232.js | 35 KB | — | ✓ | 3rd |
| https://static.crunchyroll.com/cr-acquisition/index-536eaa00.b6b3f80fb50dcb7c9b8b.js | 12 KB | — | ✓ | 3rd |
| https://static.crunchyroll.com/analytics/cr-eec-8.10.1.js | 11 KB | — | ✓ | 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
DPage Weight InventoryAction84 resources · 3.8 MB · 251 KB savings availableFIX
~251.0 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 84 resources | 3.8 MiB | ||||||
BImage Optimization16 images, 0 KB saveableREVIEW
BJS Execution Cost816ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.crunchyroll.com/ | 305ms | 16ms | 1ms | 3rd |
| Unattributable | 125ms | 32ms | 0ms | 3rd |
| https://static.crunchyroll.com/cr-acquisition/landing-start.9233fe9779ae507ba02d.js | 113ms | 95ms | 1ms | 3rd |
| https://cdn.ketchjs.com/ketchtag/stable/v2.12/ketch-sdk.js | 109ms | 74ms | 34ms | 3rd |
| https://static.crunchyroll.com/cr-acquisition/index-1d1fa024.90beed1b7f6f9bee5931.js | 100ms | 98ms | 0ms | 3rd |
| https://static.crunchyroll.com/cr-acquisition/index-9a8b795a.3ee0b69b049182bd3e30.js | 64ms | 58ms | 1ms | 3rd |
A+Text CompressionAll text resources are compressedPASS
A+Font Loading6 fonts (630 KB)PASS
Web fonts
6
630 KB total
Render-blocking
0
of 6
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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 ~270 KB and ~540 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
AHTTP Cachingmax-age=3600 (1 hour)PASS
max-age=3600
| Directive | Value | Meaning |
|---|---|---|
| max-age | 3600 | Cache for 1 hour |
Network Waterfall84 requests over 1658msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.crunchyroll.com www.crunchyroll.com | Other | 305ms | 3 KB | — | $4/mo | Costly |
Unattributable Unattributable | Other | 125ms | 0 KB | — | $2/mo | Optional |
static.crunchyroll.com static.crunchyroll.com | Other | 113ms | 13 KB | — | $1/mo | Optional |
cdn.ketchjs.com cdn.ketchjs.com | Other | 109ms | 259 KB | 63% | $1/mo | Optional |
static.crunchyroll.com static.crunchyroll.com | Other | 100ms | 10 KB | — | $1/mo | Optional |
static.crunchyroll.com static.crunchyroll.com | Other | 64ms | 9 KB | — | $1/mo | Optional |
These scripts may cost more than they're worth
- www.crunchyroll.com adds 305ms and costs ~$4/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.crunchyroll.com takes 305ms 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
63% of cdn.ketchjs.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