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.
960 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
2.85 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
146 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.001
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.39 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.
3.06 s
Page Load Progression
FPage Weight BudgetAction2.7 MB transferred, 126 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
DJS BundlesAction14 scripts, 370 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://oc-presentation.elearning.uni-hannover.de/paella7/ui/paella-player.js | 362 KB | 231 KB (64%) | ✓ | 3rd |
| https://www.uni-hannover.de/typo3conf/ext/luh_website/Resources/Public/Build/JavaScript/app.min.js?1776767856 | 161 KB | 100 KB (62%) | ✓ | 3rd |
| https://www.uni-hannover.de/typo3conf/ext/t3luhunisearch/Resources/Public/JavaScript/t3luhunisearch-min.js?1774597078 | 40 KB | 39 KB (99%) | ✓ | 3rd |
| https://www.uni-hannover.de/typo3conf/ext/t3luhepv/Resources/Public/JavaScript/t3luhepv-min.js?1776333487 | 3 KB | — | ✓ | 3rd |
| https://www.uni-hannover.de/typo3conf/ext/t3luhpublications/Resources/Public/JavaScript/filter.js?1771337314 | 1 KB | — | ✓ | 3rd |
| https://www.uni-hannover.de/typo3conf/ext/t3luhresprojects/Resources/Public/JavaScript/filter.js?1771337331 | 1 KB | — | ✓ | 3rd |
| https://www.uni-hannover.de/typo3conf/ext/t3luhtds/Resources/Public/Js/datepicker.min.js?1775634191 | 6 KB | — | ✓ | 3rd |
| https://www.uni-hannover.de/typo3conf/ext/luhevents/Resources/Public/Js/flatpickr.min.js?1771336948 | 15 KB | — | ✓ | 3rd |
| https://www.uni-hannover.de/typo3conf/ext/luhevents/Resources/Public/Js/flatpickr-init.js?1771336948 | 1 KB | — | ✓ | 3rd |
| https://www.webstats-luis.uni-hannover.de/matomo.js | 22 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
DPage Weight InventoryAction126 resources · 2.7 MB · 370 KB savings availableFIX
~370.2 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 126 resources | 2.7 MiB | ||||||
CImage OptimizationAction42 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
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
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
CJS Execution CostAction1069ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://oc-presentation.elearning.uni-hannover.de/paella7/ui/paella-player.js | 429ms | 364ms | 55ms | 3rd |
| https://www.uni-hannover.de/typo3conf/ext/luh_website/Resources/Public/Build/JavaScript/app.min.js?1776767856 | 344ms | 165ms | 14ms | 3rd |
| Unattributable | 164ms | 11ms | 0ms | 3rd |
| https://www.uni-hannover.de/ | 132ms | 2ms | 0ms | 3rd |
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
BHTTP Cachingmax-age=0REVIEW
max-age=0
| Directive | Value | Meaning |
|---|---|---|
| max-age | 0 | Cache for 0 seconds |
A+Text CompressionAll text resources are compressedPASS
A+Font Loading5 fonts (83 KB)PASS
Web fonts
5
83 KB total
Render-blocking
0
of 5
Dominant font-display
swap
Most common across fonts
Font loading timeline
- 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 ~6 KB and ~12 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall126 requests over 2066msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
oc-presentation.elearning.uni-hannover.de oc-presentation.elearning.uni-hannover.de | Other | 429ms | 362 KB | 64% | €5/mo | Costly |
www.uni-hannover.de www.uni-hannover.de | Other | 344ms | 161 KB | 62% | €4/mo | Costly |
Unattributable Unattributable | Other | 164ms | 0 KB | — | €2/mo | Optional |
www.uni-hannover.de www.uni-hannover.de | Other | 132ms | 18 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- oc-presentation.elearning.uni-hannover.de adds 429ms and costs ~€5/month
- www.uni-hannover.de adds 344ms 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
oc-presentation.elearning.uni-hannover.de takes 429ms 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
64% of oc-presentation.elearning.uni-hannover.de'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
www.uni-hannover.de takes 344ms 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
62% of www.uni-hannover.de'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