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.
764 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
884 ms
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
0 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.008
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.21 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.
884 ms
Page Load Progression
475 ms
949 ms
1.4 s
1.9 s
2.4 s
2.8 s
3.3 s
3.8 sFPage Weight BudgetAction15.6 MB transferred, 40 requestsFIX
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
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
DPage Weight InventoryAction40 resources · 15.6 MB · 203 KB savings availableFIX
~203.2 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 40 resources | 15.6 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction18 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
CJS BundlesAction8 scripts, 203 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.uni-leipzig.de/_assets/89f4369f29e16b23ff4835f5790afe07/EyeAble/public/js/eyeAble.js | 149 KB | 106 KB (72%) | ✓ | 3rd |
| https://www.uni-leipzig.de/typo3temp/assets/compressed/merged-f8b1c8b694097dc6826a1de0847a6972-5352514a2a146f83acfddc73eee7ee94.js.gz?1776760952 | 124 KB | 77 KB (62%) | ✓ | 3rd |
| https://www.uni-leipzig.de/typo3temp/assets/compressed/Form.min-8335b53c0e6b4e730f82b093a21f23e5.js.gz?1776760953 | 27 KB | 20 KB (75%) | ✓ | 3rd |
| https://www.uni-leipzig.de/typo3temp/assets/compressed/merged-7e54635e25d3fd32cf7c8658e0c6fa94-96ff2ea98aaf817e1763062637fb1be9.js.gz?1776760953 | 1 KB | — | ✓ | 3rd |
| https://uni.wwwstat.rz.uni-leipzig.de/piwik.js | 25 KB | — | ✓ | 3rd |
| https://www.uni-leipzig.de/_assets/89f4369f29e16b23ff4835f5790afe07/EyeAble/eyeAbleInclude.js?1776760583 | 5 KB | — | ✓ | 3rd |
| https://www.uni-leipzig.de/typo3temp/assets/compressed/PowermailCondition.min-db4f9f243b84d31833c239af0efcd594.js.gz?1776760953 | 3 KB | — | ✓ | 3rd |
| https://www.uni-leipzig.de/_assets/89f4369f29e16b23ff4835f5790afe07/EyeAble/config/uni-leipzig.js | 1 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
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
A+JS Execution Cost455ms total JS executionPASS
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 213ms | 9ms | 0ms | 3rd |
| https://www.uni-leipzig.de/ | 142ms | 4ms | 0ms | 3rd |
| https://www.uni-leipzig.de/typo3temp/assets/compressed/merged-f8b1c8b694097dc6826a1de0847a6972-5352514a2a146f83acfddc73eee7ee94.js.gz?1776760952 | 100ms | 74ms | 8ms | 3rd |
A+Font Loading2 fonts (330 KB)PASS
Web fonts
2
330 KB total
Render-blocking
0
of 2
Dominant font-display
swap
Most common across fonts
Font loading timeline
- 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
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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 ~264 KB and ~528 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall40 requests over 1553msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 213ms | 0 KB | — | €2/mo | Costly |
www.uni-leipzig.de www.uni-leipzig.de | Other | 142ms | 47 KB | — | €1/mo | Optional |
www.uni-leipzig.de www.uni-leipzig.de | Other | 100ms | 124 KB | 62% | €1/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 213ms and costs ~€2/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 213ms 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-leipzig.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