Performance
· 17 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.
1.73 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
8.60 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
138 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.218
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
6.46 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.
8.64 s
Page Load Progression
FPage Weight BudgetAction4.2 MB transferred, 48 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 InventoryAction48 resources · 4.2 MB · 186 KB savings availableFIX
~186.4 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 48 resources | 4.2 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization12 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
CJS Execution CostAction1657ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.ruhr-uni-bochum.de/de | 579ms | 13ms | 1ms | 3rd |
| https://www.ruhr-uni-bochum.de/sites/default/files/js/js_04Vs-H9jK7kZ8dPGYnFdD2qpd6T7EjOn7yu_Mi3R6Oo.js?scope=footer&delta=1&language=de&theme=rub&include=eJxtiEEOwyAMBD-E4idFJlklFgYjwFGe39JWPeWyMzvwdTNLgjdyVeGygfAQA-6hUhLtzSvr8rthTvVWrYOkyAiZh2WjL0LzSJE7pqyHWmSliJMvMW_9Uy_ZYfS3F5-nOZ0 | 446ms | 349ms | 30ms | 3rd |
| Unattributable | 404ms | 15ms | 0ms | 3rd |
| https://www.ruhr-uni-bochum.de/sites/default/files/js/js_Or69rxs_88oGVinF3LTmYord3SV3R6sh16BzCKx44oQ.js?scope=footer&delta=3&language=de&theme=rub&include=eJxtiEEOwyAMBD-E4idFJlklFgYjwFGe39JWPeWyMzvwdTNLgjdyVeGygfAQA-6hUhLtzSvr8rthTvVWrYOkyAiZh2WjL0LzSJE7pqyHWmSliJMvMW_9Uy_ZYfS3F5-nOZ0 | 140ms | 109ms | 25ms | 3rd |
| https://video.ruhr-uni-bochum.de/js/mediaEmbed.js.php | 88ms | 52ms | 24ms | 3rd |
CJS BundlesAction7 scripts, 186 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.ruhr-uni-bochum.de/sites/default/files/js/js_04Vs-H9jK7kZ8dPGYnFdD2qpd6T7EjOn7yu_Mi3R6Oo.js?scope=footer&delta=1&language=de&theme=rub&include=eJxtiEEOwyAMBD-E4idFJlklFgYjwFGe39JWPeWyMzvwdTNLgjdyVeGygfAQA-6hUhLtzSvr8rthTvVWrYOkyAiZh2WjL0LzSJE7pqyHWmSliJMvMW_9Uy_ZYfS3F5-nOZ0 | 140 KB | 63 KB (45%) | ✓ | 3rd |
| https://www.ruhr-uni-bochum.de/sites/default/files/js/js_Or69rxs_88oGVinF3LTmYord3SV3R6sh16BzCKx44oQ.js?scope=footer&delta=3&language=de&theme=rub&include=eJxtiEEOwyAMBD-E4idFJlklFgYjwFGe39JWPeWyMzvwdTNLgjdyVeGygfAQA-6hUhLtzSvr8rthTvVWrYOkyAiZh2WjL0LzSJE7pqyHWmSliJMvMW_9Uy_ZYfS3F5-nOZ0 | 96 KB | 54 KB (57%) | ✓ | 3rd |
| https://video.ruhr-uni-bochum.de/js/mediaEmbed.js.php | 54 KB | 39 KB (74%) | ✓ | 3rd |
| https://statistic.ruhr-uni-bochum.de/matomo.js | 45 KB | 30 KB (67%) | ✓ | 3rd |
| https://www.ruhr-uni-bochum.de/core/assets/vendor/loadjs/loadjs.min.js?v=4.3.0 | 1 KB | — | ✓ | 3rd |
| https://www.ruhr-uni-bochum.de/sites/default/files/js/js_EUCNs45PTfsdslOEV9ZTS1ILgIWPLKxHZ1Z9L9lurG4.js?scope=footer&delta=5&language=de&theme=rub&include=eJxtiEEOwyAMBD-E4idFJlklFgYjwFGe39JWPeWyMzvwdTNLgjdyVeGygfAQA-6hUhLtzSvr8rthTvVWrYOkyAiZh2WjL0LzSJE7pqyHWmSliJMvMW_9Uy_ZYfS3F5-nOZ0 | 2 KB | — | ✓ | 3rd |
| https://www.ruhr-uni-bochum.de/themes/custom/rub/dist/lib/modernizr.custom.min.js?v=3.3.1 | 4 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
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+Font Loading12 fonts (230 KB)PASS
Web fonts
12
230 KB total
Render-blocking
0
of 12
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
- 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 ~39 KB and ~78 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource Hints7 hints, 0 missing preconnectsPASS
Current Resource Hints
7 resource hints configured
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall48 requests over 7697msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.ruhr-uni-bochum.de www.ruhr-uni-bochum.de | Other | 579ms | 26 KB | — | €6/mo | Costly |
www.ruhr-uni-bochum.de www.ruhr-uni-bochum.de | Other | 446ms | 140 KB | 45% | €5/mo | Costly |
Unattributable Unattributable | Other | 404ms | 0 KB | — | €4/mo | Costly |
www.ruhr-uni-bochum.de www.ruhr-uni-bochum.de | Other | 140ms | 96 KB | 57% | €2/mo | Optional |
video.ruhr-uni-bochum.de video.ruhr-uni-bochum.de | Other | 88ms | 54 KB | 74% | €1/mo | Optional |
These scripts may cost more than they're worth
- www.ruhr-uni-bochum.de adds 579ms and costs ~€6/month
- www.ruhr-uni-bochum.de adds 446ms and costs ~€5/month
- Unattributable adds 404ms 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.ruhr-uni-bochum.de takes 579ms 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.ruhr-uni-bochum.de takes 446ms 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 404ms 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
57% of www.ruhr-uni-bochum.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
74% of video.ruhr-uni-bochum.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