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.
6.41 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
9.27 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
103 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.
6.98 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.
9.38 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 sDThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS BundlesAction3 scripts, 614 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.mobygames.com/static/js/shared.9361b94c.js | 625 KB | 478 KB (77%) | ✓ | 3rd |
| https://www.mobygames.com/static/js/main.7c0900e4.js | 84 KB | 73 KB (87%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-DF0Y2K8D8P | 158 KB | 64 KB (40%) | ✓ | 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
FPage Weight InventoryAction68 resources · 1.4 MB · 614 KB savings availableFIX
~614.2 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 68 resources | 1.4 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BPage Weight Budget1.4 MB transferred, 68 requestsREVIEW
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
CImage OptimizationAction56 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
CJS Execution CostAction1738ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 750ms | 178ms | 0ms | 3rd |
| https://www.mobygames.com/static/js/shared.9361b94c.js | 381ms | 298ms | 8ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-DF0Y2K8D8P | 286ms | 237ms | 43ms | 3rd |
| https://www.mobygames.com/ | 171ms | 23ms | 4ms | 3rd |
| https://www.mobygames.com/static/js/main.7c0900e4.js | 149ms | 2ms | 1ms | 3rd |
A+Text CompressionAll text resources are compressedPASS
A+Font Loading2 fonts (61 KB)PASS
Web fonts
2
61 KB total
Render-blocking
0
of 2
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+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 Waterfall68 requests over 1614msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 750ms | 0 KB | — | $10/mo | Costly |
www.mobygames.com www.mobygames.com | Other | 381ms | 625 KB | 77% | $5/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 286ms | 158 KB | 40% | $4/mo | Costly |
www.mobygames.com www.mobygames.com | Other | 171ms | 14 KB | — | $2/mo | Optional |
www.mobygames.com www.mobygames.com | Other | 149ms | 84 KB | 87% | $2/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 750ms and costs ~$10/month
- www.mobygames.com adds 381ms and costs ~$5/month
- Google Tag Manager adds 286ms 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
Unattributable takes 750ms 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.mobygames.com takes 381ms 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
77% of www.mobygames.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
Google Tag Manager takes 286ms 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
87% of www.mobygames.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