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.
1.66 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
11.93 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
764 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.159
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
6.73 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.
13.03 s
Page Load Progression
921 ms
1.8 s
2.8 s
3.7 s
4.6 s
5.5 s
6.4 s
7.4 sFPage Weight BudgetAction21.2 MB transferred, 511 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
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 CostAction6013ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.lufthansa.com/etc/designs/dcep/clientlib-all/vite/js/3214b722.chunk.js | 2061ms | 1933ms | 2ms | 3rd |
| https://www.lufthansa.com/digitalhangar/design-system/releases/v1.26.2/standalone/packages/maui-design-system.js | 1255ms | 1054ms | 8ms | 3rd |
| Unattributable | 1238ms | 79ms | 0ms | 3rd |
| https://www.lufthansa.com/us/en/homepage | 639ms | 29ms | 6ms | 3rd |
| https://shop.lufthansa.com/booking/api/prefetch | 239ms | 175ms | 2ms | 3rd |
| https://www.lufthansa.com/etc/designs/dcep/clientlib-all/vite/js/app.65c13881.js | 183ms | 142ms | 0ms | 3rd |
| https://www.lufthansa.com/etc/designs/dcep/clientlib-all/vite/js/38fd48be.chunk.js | 162ms | 13ms | 0ms | 3rd |
| https://www.lufthansa.com/cdn-cgi/challenge-platform/scripts/jsd/main.js | 95ms | 90ms | 2ms | 3rd |
| https://tags.tiqcdn.com/utag/lufthansa/main/prod/utag.js | 73ms | 48ms | 15ms | 3rd |
| https://www.lufthansa.com/etc.clientlibs/clientlibs/granite/jquery/granite.ed0d934d509c9dab702088c125c92b4f.js | 68ms | 65ms | 0ms | 3rd |
FJS BundlesAction400 scripts, 871 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.lufthansa.com/etc/designs/dcep/clientlib-all/vite/js/3214b722.chunk.js | 345 KB | 166 KB (48%) | ✓ | 3rd |
| https://www.lufthansa.com/etc/designs/dcep/clientlib-all/vite/js/360cb2ea.chunk.js | 167 KB | 150 KB (90%) | ✓ | 3rd |
| https://www.lufthansa.com/etc/designs/dcep/clientlib-all/vite/js/eb345d23.chunk.js | 264 KB | 134 KB (51%) | ✓ | 3rd |
| https://www.lufthansa.com/etc/designs/dcep/clientlib-all/vite/js/cf6255a2.chunk.js | 118 KB | 76 KB (65%) | ✓ | 3rd |
| https://www.lufthansa.com/etc.clientlibs/clientlibs/granite/jquery.1fc733054ddb2e2fcd4a0f763671047b.js | 87 KB | 57 KB (66%) | ✗ | 3rd |
| https://www.lufthansa.com/etc/designs/dcep/clientlib-all/vite/js/d10bccbc.chunk.js | 52 KB | 45 KB (86%) | ✓ | 3rd |
| https://www.lufthansa.com/etc/designs/dcep/clientlib-all/vite/js/38fd48be.chunk.js | 75 KB | 45 KB (60%) | ✓ | 3rd |
| https://www.lufthansa.com/digitalhangar/design-system/releases/v1.26.2/standalone/packages/maui-design-system.js | 308 KB | 42 KB (14%) | ✗ | 3rd |
| https://tags.tiqcdn.com/utag/lufthansa/main/prod/utag.js | 120 KB | 39 KB (34%) | ✓ | 3rd |
| https://www.lufthansa.com/etc/designs/dcep/clientlib-all/vite/js/9792a05f.chunk.js | 66 KB | 34 KB (51%) | ✓ | 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 InventoryAction511 resources · 21.2 MB · 871 KB savings availableFIX
~871.1 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 511 resources | 21.2 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction38 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
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
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
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 Loading22 fonts (1340 KB)PASS
Web fonts
22
1340 KB total
Render-blocking
0
of 22
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
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 ~469 KB and ~938 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall511 requests over 7257msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.lufthansa.com www.lufthansa.com | Other | 2061ms | 345 KB | 48% | €22/mo | Costly |
www.lufthansa.com www.lufthansa.com | Other | 1255ms | 308 KB | 14% | €14/mo | Costly |
Unattributable Unattributable | Other | 1238ms | 0 KB | — | €13/mo | Costly |
www.lufthansa.com www.lufthansa.com | Other | 639ms | 36 KB | — | €7/mo | Costly |
shop.lufthansa.com shop.lufthansa.com | Other | 239ms | 16 KB | — | €3/mo | Costly |
www.lufthansa.com www.lufthansa.com | Other | 183ms | 18 KB | — | €2/mo | Optional |
www.lufthansa.com www.lufthansa.com | Other | 162ms | 75 KB | 60% | €2/mo | Optional |
www.lufthansa.com www.lufthansa.com | Other | 95ms | 0 KB | — | €1/mo | Optional |
tags.tiqcdn.com tags.tiqcdn.com | Other | 73ms | 120 KB | 34% | €1/mo | Optional |
www.lufthansa.com www.lufthansa.com | Other | 68ms | 3 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- www.lufthansa.com adds 2061ms and costs ~€22/month
- www.lufthansa.com adds 1255ms and costs ~€14/month
- Unattributable adds 1238ms and costs ~€13/month
- www.lufthansa.com adds 639ms and costs ~€7/month
- shop.lufthansa.com adds 239ms and costs ~€3/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.lufthansa.com takes 2061ms 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.lufthansa.com takes 1255ms 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 1238ms 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.lufthansa.com takes 639ms 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
shop.lufthansa.com takes 239ms 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
60% of www.lufthansa.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