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https://appcenter.ms

Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
91
GRADE
A
FIX
1
REVIEW
5
PASS
9
INFO
2

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop
73
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
100
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
77
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
100
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

4.44 s

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

4.44 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

2 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.023

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

4.44 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.

5.02 s

Page Load Progression

375 ms
750 ms
1.1 s
1.5 s
1.9 s
2.2 s
2.6 s
3.0 s
Checks
17
9 PASS 5 REVIEW 1 FIX
F
HTTP Caching
Action
No cache headers
FIX
No cache headers
Warning::
No Cache-Control header found
Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.

No Cache-Control header

Adding a Cache-Control header can significantly improve repeat-visit performance.

B
Page Weight Budget
1.4 MB transferred, 17 requests
REVIEW
1.4 MB transferred, 17 requests
Info::
Page weighs 1.4 MB (1.4 MB transferred)
Info::
CSS is 603 KB — consider purging unused styles
Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.
Got: 603 KB
Info::
17 HTTP requests
Info::
Estimated 0.29 g CO2 per page load
1.4 MB / 2.4 MB budget
1.4 MB transferred
17 requests
0.29 g CO2 per page load
CSS 603.0 KiB 43%
Images 590.7 KiB 42%
Fonts 120.4 KiB 9%
JavaScript 46.3 KiB 3%
HTML 33.3 KiB 2%
Other 10.0 KiB 1%
Other 234 B 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Under budget

Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.

Why this matters

CSS bundle is large — purge unused styles (PurgeCSS, Tailwind JIT) to reduce CSS payload.

Source: web.dev

C
Image Optimization
Action
7 images, 0 KB saveable
REVIEW
7 images, 0 KB saveable
Warning::
https://appcenter.ms/images/app-center-hero.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://appcenter.ms/images/app-center-diagnostics... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://appcenter.ms/images/app-center-live-analyt... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://appcenter.ms/images/app-center-analytics-g... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://appcenter.ms/images/logo-twitter.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://appcenter.ms/images/logo-linkedin.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://appcenter.ms/images/logo-microsoft.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
7 images 591 KB
0 oversized -0 KB
7 legacy format
7 missing dimensions CLS risk

Set explicit width and height to prevent CLS.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

B
JS Execution Cost
669ms total JS execution
REVIEW
669ms total JS execution
Warning::
Unattributable: 281ms CPU time
Info::
https://appcenter.ms/: 230ms CPU time
Info::
https://az416426.vo.msecnd.net/next/ai.2.min.js: 104ms CPU time
Info::
https://appcenter.ms/styles/mwf-west-european-defa...: 53ms CPU time
Warning::
Third-party scripts: 385ms (58% of total)

Main Thread Breakdown

Other 42% Style & Layout 27% Script Evaluation 17% Parse HTML & CSS 7% Rendering 4%
ScriptTotalScriptingParse/CompileParty
Unattributable281ms9ms0ms3rd
https://appcenter.ms/230ms16ms2ms1st
https://az416426.vo.msecnd.net/next/ai.2.min.js104ms88ms9ms3rd
https://appcenter.ms/styles/mwf-west-european-default.min.css53ms0ms0ms1st
B
Page Weight Inventory
17 resources · 1.4 MB · 0 KB savings available
REVIEW
17 resources · 1.4 MB · 0 KB savings available
Warning::
Page weight 380 KB over 1MB target
Got: 1.4 MB Expected: ≤ 1 MB
Info::
7 third-party resources (12% of weight)
Info::
2 resources over 200KB
17 resources · 1.4 MiB · 7 third-party 380.0 KiB over 1MB target
CSS 43% · 603.0 KiB
Image 43% · 600.7 KiB
Font 9% · 120.4 KiB
JavaScript 3% · 46.3 KiB
Document 2% · 33.3 KiB
Other 0% · 234 B
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Third-Party Impact
12% third-party, 0 ms blocking
PASS
12% third-party, 0 ms blocking
Info::
Third-party code accounts for 12% of page weight (166.9 KiB of 1.4 MiB)
Info::
Third-party blocking time is low (0 ms)
88%
First-party Third-party
A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+
Font Loading
4 fonts (120 KB)
PASS
4 fonts (120 KB)
Info::
4 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

4

120 KB total

Render-blocking

0

of 4

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 1.0 s 2.0 s 3.0 s 4.0 s FCP 4.4 s LCP 4.4 shttps://c.s-microsoft.com/static/fonts/segoe-ui/west-european/normal/latest.woff2latest.woff2 https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/normal/latest.woff2 — 33.5 KiB — 64 ms — font-display: swaphttps://c.s-microsoft.com/static/fonts/segoe-ui/west-european/Semilight/latest.woff2latest.woff2 https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/Semilight/latest.woff2 — 28.4 KiB — 59 ms — font-display: swaphttps://c.s-microsoft.com/static/fonts/segoe-ui/west-european/Semibold/latest.woff2latest.woff2 https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/Semibold/latest.woff2 — 28.9 KiB — 60 ms — font-display: swaphttps://c.s-microsoft.com/static/fonts/segoe-ui/west-european/Bold/latest.woff2latest.woff2 https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/Bold/latest.woff2 — 29.6 KiB — 61 ms — font-display: swap
latest.woff2 woff2 swap
Size 33 KB
Load time 64 ms
Start 1.1 s
Risk FOUT — text flashes from fallback to web font
latest.woff2 woff2 swap
Size 28 KB
Load time 59 ms
Start 1.1 s
Risk FOUT — text flashes from fallback to web font
latest.woff2 woff2 swap
Size 29 KB
Load time 60 ms
Start 1.1 s
Risk FOUT — text flashes from fallback to web font
latest.woff2 woff2 swap
Size 30 KB
Load time 61 ms
Start 1.1 s
Risk FOUT — text flashes from fallback to web font
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+
JS Bundles
1 scripts, 0 KB unused
PASS
1 scripts, 0 KB unused
0 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://az416426.vo.msecnd.net/next/ai.2.min.js46 KB—✓3rd
A+
Resource Caching
All resources properly cached
PASS
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
No render-blocking resources detected
A+
Resource Hints
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
A+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
Network Waterfall
17 requests over 3537ms
INFO
0 ms 1.0 s 2.0 s 3.0 s 4.0 s FCP 4.4 s LCP 4.4 shttps://appcenter.ms// https://appcenter.ms/ — 200 — 33.3 KiB — 449 ms — h2https://appcenter.ms/styles/mwf-west-european-default.min.css/styles/mwf-west-european-default.m... https://appcenter.ms/styles/mwf-west-european-default.min.css — 200 — 603.0 KiB — 632 ms — h2https://appcenter.ms/images/logo-microsoft.svg/images/logo-microsoft.svg https://appcenter.ms/images/logo-microsoft.svg — 200 — 9.8 KiB — 128 ms — h2https://appcenter.ms/images/app-center-hero.svg/images/app-center-hero.svg https://appcenter.ms/images/app-center-hero.svg — 200 — 80.2 KiB — 475 ms — h2https://appcenter.ms/images/app-center-diagnostics@2x.png/images/app-center-diagnostics@2x.p... https://appcenter.ms/images/app-center-diagnostics@2x.png — 200 — 128.2 KiB — 479 ms — h2https://appcenter.ms/images/app-center-live-analytics@2x.png/images/app-center-live-analytics@2... https://appcenter.ms/images/app-center-live-analytics@2x.png — 200 — 144.6 KiB — 490 ms — h2https://appcenter.ms/images/app-center-analytics-graphs.svg/images/app-center-analytics-graphs... https://appcenter.ms/images/app-center-analytics-graphs.svg — 200 — 221.3 KiB — 580 ms — h2https://appcenter.ms/images/logo-twitter.svg/images/logo-twitter.svg https://appcenter.ms/images/logo-twitter.svg — 200 — 3.3 KiB — 331 ms — h2https://appcenter.ms/images/logo-linkedin.svg/images/logo-linkedin.svg https://appcenter.ms/images/logo-linkedin.svg — 200 — 3.4 KiB — 350 ms — h2https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/normal/latest.woff2c.s-microsoft.com/static/fonts/sego... https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/normal/latest.woff2 — 200 — 33.5 KiB — 64 ms — h2https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/Semilight/latest.woff2c.s-microsoft.com/static/fonts/sego... https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/Semilight/latest.woff2 — 200 — 28.4 KiB — 59 ms — h2https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/Semibold/latest.woff2c.s-microsoft.com/static/fonts/sego... https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/Semibold/latest.woff2 — 200 — 28.9 KiB — 60 ms — h2https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/Bold/latest.woff2c.s-microsoft.com/static/fonts/sego... https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/Bold/latest.woff2 — 200 — 29.6 KiB — 61 ms — h2https://az416426.vo.msecnd.net/next/ai.2.min.jsaz416426.vo.msecnd.net/next/ai.2.mi... https://az416426.vo.msecnd.net/next/ai.2.min.js — 200 — 46.3 KiB — 139 ms — h2https://appcenter.ms/favicon.ico/favicon.ico https://appcenter.ms/favicon.ico — 200 — 10.0 KiB — 110 ms — h2https://dc.services.visualstudio.com/v2/trackdc.services.visualstudio.com/v2/tra... https://dc.services.visualstudio.com/v2/track — 204 — 0 B — 198 ms — h2https://dc.services.visualstudio.com/v2/trackdc.services.visualstudio.com/v2/tra... https://dc.services.visualstudio.com/v2/track — 400 — 234 B — 83 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
58% of JavaScript execution is third-party
First-party Third-party 385ms · 46KB · $5/mo
Unattributable
Other
Costly
Execution 281ms
Transfer 0 KB
Monthly Cost $4/mo
az416426.vo.msecnd.net
Other
Optional
Execution 104ms
Transfer 46 KB
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • Unattributable adds 281ms and costs ~$4/month

58% of JavaScript execution time comes from third-party scripts.

Why this matters

Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.

Learn more ▾

Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.

Source: web.dev / HTTP Archive Web Almanac

Unattributable takes 281ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

How third-party costs are calculated

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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