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.
972 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.25 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
18 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.
1.06 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.
2.40 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
DPage Weight InventoryAction110 resources · 2.0 MB · 136 KB savings availableFIX
~136.1 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 110 resources | 2.0 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CPage Weight BudgetAction2.0 MB transferred, 110 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
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
BJS Execution Cost856ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.computer.org/ | 266ms | 43ms | 12ms | 3rd |
| Unattributable | 148ms | 8ms | 0ms | 3rd |
| https://www.computer.org/_next/static/chunks/7023-de08e90fe6034213.js | 128ms | 111ms | 7ms | 3rd |
| https://cmp.osano.com/AzyzptTmRlqVd2LRf/dc14b2c6-ae04-4497-98f0-2bdbdd2af415/osano.js | 113ms | 98ms | 3ms | 3rd |
| https://www.computer.org/_next/static/chunks/fd9d1056-4895dfff47e87bd7.js | 72ms | 47ms | 6ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-N7782B0VN4&cx=c>m=4e64h1 | 70ms | 57ms | 12ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-PPQ37HW | 58ms | 51ms | 7ms | 3rd |
BJS Bundles29 scripts, 136 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-N7782B0VN4&cx=c>m=4e64h1 | 172 KB | 73 KB (42%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-PPQ37HW | 136 KB | 63 KB (47%) | ✓ | 3rd |
| https://www.computer.org/_next/static/chunks/5223-3dd61149aa470874.js | 3 KB | — | ✓ | 3rd |
| blob:https://www.computer.org/ed1bafa5-a340-47fb-9700-e36c9070cece | -0 KB | — | ✓ | 3rd |
| https://www.computer.org/_next/static/chunks/7023-de08e90fe6034213.js | 31 KB | — | ✓ | 3rd |
| https://www.computer.org/_next/static/chunks/main-app-70fb7231193511ce.js | 1 KB | — | ✓ | 3rd |
| https://www.computer.org/_next/static/chunks/app/global-error-70363a7844e983ef.js | 3 KB | — | ✓ | 3rd |
| https://www.computer.org/_next/static/chunks/998-4bc3ad25ed52586d.js | 10 KB | — | ✓ | 3rd |
| https://www.computer.org/_next/static/chunks/6164-9f27c05a522a8294.js | 7 KB | — | ✓ | 3rd |
| https://www.computer.org/_next/static/chunks/231-5d380eb9d70f48bb.js | 7 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
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
AImage Optimization51 images, 0 KB saveablePASS
A+Font Loading4 fonts (131 KB)PASS
Web fonts
4
131 KB total
Render-blocking
0
of 4
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
Network Waterfall110 requests over 3502msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.computer.org www.computer.org | Other | 266ms | 121 KB | — | $4/mo | Costly |
Unattributable Unattributable | Other | 148ms | 0 KB | — | $2/mo | Optional |
www.computer.org www.computer.org | Other | 128ms | 31 KB | — | $2/mo | Optional |
cmp.osano.com cmp.osano.com | Other | 113ms | 39 KB | — | $2/mo | Optional |
www.computer.org www.computer.org | Other | 72ms | 53 KB | — | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 70ms | 172 KB | 42% | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 58ms | 136 KB | 47% | $1/mo | Optional |
These scripts may cost more than they're worth
- www.computer.org adds 266ms 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.computer.org takes 266ms 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