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.
7.71 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
20.96 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
2.65 s
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.
7.71 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.
21.66 s
Page Load Progression
FPage Weight BudgetAction4.8 MB transferred, 124 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
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 CostAction7016ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 2441ms | 593ms | 0ms | 3rd |
| https://www.chess.com/ | 1019ms | 52ms | 26ms | 3rd |
| https://www.chess.com/bundles/app/vite/common.Dznmi7HDZK.chunk.js | 995ms | 916ms | 3ms | 3rd |
| https://www.chess.com/bundles/app/js/web.chunk.client.db655030.js | 471ms | 387ms | 51ms | 3rd |
| https://www.chess.com/bundles/app/js/global-app-init.chunk.client.e02dc005.js | 377ms | 338ms | 16ms | 3rd |
| https://www.chess.com/bundles/app/js/sentry.client.ab73093b.js | 288ms | 221ms | 22ms | 3rd |
| https://www.chess.com/bundles/app/js/index.client.644c35a4.js | 195ms | 160ms | 31ms | 3rd |
| https://www.chess.com/bundles/app/js/landing-page.client.c273ac3d.js | 169ms | 121ms | 44ms | 3rd |
| https://www.chess.com/bundles/app/js/turnstile.client.fdded8a7.js | 162ms | 158ms | 3ms | 3rd |
| https://www.chess.com/bundles/app/js/coach-client.chunk.client.b5b3bfce.js | 146ms | 138ms | 7ms | 3rd |
Showing top 10 of 17 scripts
FJS BundlesAction61 scripts, 572 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.chess.com/bundles/app/js/vue.dll.c1ed70f2.js | 213 KB | 153 KB (72%) | ✓ | 3rd |
| https://www.chess.com/bundles/app/js/web.chunk.client.c501b5ae.js | 106 KB | 99 KB (94%) | ✓ | 3rd |
| https://www.chess.com/bundles/app/js/web.chunk.client.cc4f64ab.js | 106 KB | 99 KB (94%) | ✓ | 3rd |
| https://www.chess.com/bundles/app/js/landing-page.client.c273ac3d.js | 77 KB | 57 KB (75%) | ✓ | 3rd |
| https://www.chess.com/bundles/app/vite/common.AO98t6A9Lx.chunk.js | 45 KB | 42 KB (93%) | ✓ | 3rd |
| https://www.chess.com/bundles/app/vite/vendors/vue.runtime.esm-bundler.CsWIWiQsn3.js | 53 KB | 33 KB (64%) | ✗ | 3rd |
| https://www.chess.com/bundles/app/vite/common.tcMo54zQ4X.chunk.js | 38 KB | 33 KB (88%) | ✓ | 3rd |
| https://www.chess.com/bundles/app/vite/common.BBWXPFjHfi.chunk.js | 32 KB | 30 KB (96%) | ✓ | 3rd |
| https://www.chess.com/bundles/app/js/web.chunk.client.f3acd298.js | 46 KB | 25 KB (54%) | ✓ | 3rd |
| https://www.chess.com/bundles/app/js/index.client.644c35a4.js | 51 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
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 InventoryAction124 resources · 4.8 MB · 572 KB savings availableFIX
~571.7 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 124 resources | 4.8 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization24 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 Loading3 fonts (187 KB)PASS
Web fonts
3
187 KB total
Render-blocking
0
of 3
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 Hints5 hints, 0 missing preconnectsPASS
Current Resource Hints
5 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: Cloudflare
Network Waterfall124 requests over 4069msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 2441ms | 0 KB | — | $42/mo | Costly |
www.chess.com www.chess.com | Other | 1019ms | 27 KB | — | $18/mo | Costly |
www.chess.com www.chess.com | Other | 995ms | 46 KB | — | $17/mo | Costly |
www.chess.com www.chess.com | Other | 471ms | 96 KB | — | $8/mo | Costly |
www.chess.com www.chess.com | Other | 377ms | 25 KB | — | $6/mo | Costly |
www.chess.com www.chess.com | Other | 288ms | 29 KB | — | $5/mo | Costly |
www.chess.com www.chess.com | Other | 195ms | 51 KB | — | $3/mo | Optional |
www.chess.com www.chess.com | Other | 169ms | 77 KB | 75% | $3/mo | Optional |
www.chess.com www.chess.com | Other | 162ms | 7 KB | — | $3/mo | Optional |
www.chess.com www.chess.com | Other | 146ms | 13 KB | — | $3/mo | Optional |
www.chess.com www.chess.com | Other | 135ms | 213 KB | 72% | $2/mo | Optional |
www.chess.com www.chess.com | Other | 122ms | 106 KB | 94% | $2/mo | Optional |
www.chess.com www.chess.com | Other | 111ms | 34 KB | — | $2/mo | Optional |
www.chess.com www.chess.com | Other | 110ms | 106 KB | 94% | $2/mo | Optional |
www.chess.com www.chess.com | Other | 95ms | 16 KB | — | $2/mo | Optional |
www.chess.com www.chess.com | Other | 91ms | 10 KB | — | $2/mo | Optional |
www.chess.com www.chess.com | Other | 88ms | 2 KB | — | $2/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 2441ms and costs ~$42/month
- www.chess.com adds 1019ms and costs ~$18/month
- www.chess.com adds 995ms and costs ~$17/month
- www.chess.com adds 471ms and costs ~$8/month
- www.chess.com adds 377ms and costs ~$6/month
- www.chess.com adds 288ms and costs ~$5/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 2441ms 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.chess.com takes 1019ms 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.chess.com takes 995ms 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.chess.com takes 471ms 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.chess.com takes 377ms 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.chess.com takes 288ms 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
75% of www.chess.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
72% of www.chess.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
94% of www.chess.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
94% of www.chess.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