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.
2.77 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
6.74 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
862 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
1.939
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
7.00 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.
8.20 s
Page Load Progression
FPage Weight BudgetAction6.4 MB transferred, 191 requestsFIX
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
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
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 CostAction3941ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.alaskaair.com/retaincontent/retrostack/_next/static/chunks/630fe265.45a806ad49ae5852.js | 1025ms | 754ms | 144ms | 3rd |
| Unattributable | 522ms | 34ms | 0ms | 3rd |
| https://www.alaskaair.com/retaincontent/retrostack/_next/static/chunks/f44aefd6.99d5d2f64ccb3b66.js | 489ms | 333ms | 66ms | 3rd |
| https://www.alaskaair.com/retaincontent/retrostack/_next/static/chunks/framework-2f3de63929c73f88.js | 459ms | 312ms | 116ms | 3rd |
| https://www.alaskaair.com/ | 350ms | 135ms | 0ms | 3rd |
| https://cdn.appdynamics.com/adrum/adrum-latest.js | 306ms | 204ms | 3ms | 3rd |
| https://cdn.optimizely.com/js/10453949094.js | 267ms | 225ms | 19ms | 3rd |
| https://www.alaskaair.com/retaincontent/retrostack/_next/static/chunks/1aac3323.f0cdb9870f5e1e44.js | 193ms | 124ms | 53ms | 3rd |
| https://www.alaskaair.com/retaincontent/retrostack/_next/static/chunks/1589-a8a5e5fa0300ae6b.js | 114ms | 104ms | 2ms | 3rd |
| https://www.alaskaair.com/retaincontent/retrostack/_next/static/chunks/cfef4c35.8645c2ff3fd038d1.js | 77ms | 46ms | 10ms | 3rd |
Showing top 10 of 12 scripts
FJS BundlesAction67 scripts, 962 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.alaskaair.com/retaincontent/retrostack/_next/static/chunks/630fe265.45a806ad49ae5852.js | 1219 KB | 342 KB (28%) | ✓ | 3rd |
| https://www.alaskaair.com/retaincontent/retrostack/_next/static/chunks/f44aefd6.99d5d2f64ccb3b66.js | 548 KB | 147 KB (27%) | ✓ | 3rd |
| https://www.alaskaair.com/retaincontent/retrostack/_next/static/chunks/1aac3323.f0cdb9870f5e1e44.js | 414 KB | 97 KB (23%) | ✓ | 3rd |
| https://contentcdnprodacct.blob.core.windows.net/online-chat/index.js | 112 KB | 81 KB (72%) | ✓ | 3rd |
| https://cdn.optimizely.com/js/10453949094.js | 173 KB | 69 KB (40%) | ✗ | 3rd |
| https://tags.tiqcdn.com/utag/alaska/main/prod/utag.js | 129 KB | 62 KB (50%) | ✓ | 3rd |
| https://cdn.appdynamics.com/adrum/adrum-latest.js | 150 KB | 57 KB (38%) | ✓ | 3rd |
| https://www.alaskaair.com/retaincontent/retrostack/_next/static/chunks/pages/_app-1df585c67203bc85.js | 79 KB | 33 KB (43%) | ✓ | 3rd |
| https://cdn.appdynamics.com/adrum-ext.306ca58e36f81225954b7b84627d2c85.js | 56 KB | 27 KB (49%) | ✓ | 3rd |
| https://www.alaskaair.com/_fs-ch-1T1wmsGaOgGaSxcX/clientdetection.js | 205 KB | 25 KB (12%) | ✓ | 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 InventoryAction191 resources · 6.4 MB · 962 KB savings availableFIX
~961.6 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 191 resources | 6.4 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization38 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
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 Loading4 fonts (189 KB)PASS
Web fonts
4
189 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 Waterfall191 requests over 8268msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.alaskaair.com www.alaskaair.com | Other | 1025ms | 1219 KB | 28% | $19/mo | Costly |
Unattributable Unattributable | Other | 522ms | 0 KB | — | $10/mo | Costly |
www.alaskaair.com www.alaskaair.com | Other | 489ms | 548 KB | 27% | $9/mo | Costly |
www.alaskaair.com www.alaskaair.com | Other | 459ms | 44 KB | — | $9/mo | Costly |
www.alaskaair.com www.alaskaair.com | Other | 350ms | 557 KB | — | $7/mo | Costly |
cdn.appdynamics.com cdn.appdynamics.com | Other | 306ms | 150 KB | 38% | $6/mo | Costly |
Optimizely cdn.optimizely.com | A/B Testing | 267ms | 173 KB | 40% | $5/mo | Costly |
www.alaskaair.com www.alaskaair.com | Other | 193ms | 414 KB | 23% | $4/mo | Optional |
www.alaskaair.com www.alaskaair.com | Other | 114ms | 27 KB | — | $2/mo | Optional |
www.alaskaair.com www.alaskaair.com | Other | 77ms | 38 KB | — | $1/mo | Optional |
2026-03-27-atmos-homepage-modal-as-var2.js 2026-03-27-atmos-homepage-modal-as-var2.js | Other | 75ms | 0 KB | — | $1/mo | Optional |
tags.tiqcdn.com tags.tiqcdn.com | Other | 65ms | 129 KB | 50% | $1/mo | Optional |
These scripts may cost more than they're worth
- www.alaskaair.com adds 1025ms and costs ~$19/month
- Unattributable adds 522ms and costs ~$10/month
- www.alaskaair.com adds 489ms and costs ~$9/month
- www.alaskaair.com adds 459ms and costs ~$9/month
- www.alaskaair.com adds 350ms and costs ~$7/month
- cdn.appdynamics.com adds 306ms and costs ~$6/month
- Optimizely adds 267ms 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
www.alaskaair.com takes 1025ms 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
Unattributable takes 522ms 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.alaskaair.com takes 489ms 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.alaskaair.com takes 459ms 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.alaskaair.com takes 350ms 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
cdn.appdynamics.com takes 306ms 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
Optimizely takes 267ms 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