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https://www.glassdoor.com

Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
76
GRADE
C
FIX
5
REVIEW
0
PASS
9
INFO
2

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

36
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
98
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.
92
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.

2.38 s

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

10.86 s

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

3.62 s

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

0.075

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

5.64 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.

18.33 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
16
9 PASS 5 FIX
F
Page Weight Budget
Action
2.7 MB transferred, 90 requests
FIX
2.7 MB transferred, 90 requests
Warning::
Page weighs 9.0 MB (2.7 MB transferred)
Warning::
JavaScript is 1.9 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.9 MB
Info::
90 HTTP requests
Info::
Estimated 0.56 g CO2 per page load
2.7 MB / 2.4 MB budget
2.7 MB transferred
90 requests
0.56 g CO2 per page load
JavaScript 1.9 MiB 69%
Images 527.6 KiB 19%
Fonts 139.0 KiB 5%
CSS 93.1 KiB 3%
HTML 62.2 KiB 2%
Other 4.1 KiB 0%
Other 3.6 KiB 0%
Other 2.3 KiB 0%
Other 1.1 KiB 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over budget

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Why this matters

JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.

Source: web.dev

D
Third-Party Impact
Action
95% third-party, 0 ms blocking
FIX
95% third-party, 0 ms blocking
Warning::
Third-party code accounts for 95% of page weight (2.5 MiB of 2.7 MiB)
Info::
Third-party blocking time is low (0 ms)
95%
First-party Third-party
F
JS Execution Cost
Action
7249ms total JS execution
FIX
7249ms total JS execution
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-PST...: 1564ms CPU time
Warning::
https://cdn.rudderlabs.com/v3/legacy/rsa.min.js: 1249ms CPU time
Warning::
https://cdnjs.cloudflare.com/ajax/libs/react/18.3....: 768ms CPU time
Warning::
Unattributable: 689ms CPU time
Warning::
https://www.glassdoor.fr/seo-pages/assets/_next/st...: 640ms CPU time
Warning::
Third-party scripts: 7249ms (100% of total)

Main Thread Breakdown

Script Evaluation 73% Other 10% Script Parsing & Compilation 9% Style & Layout 3%
ScriptTotalScriptingParse/CompileParty
https://www.googletagmanager.com/gtm.js?id=GTM-PST2JZ&l=gdGlobals1564ms1423ms56ms3rd
https://cdn.rudderlabs.com/v3/legacy/rsa.min.js1249ms1160ms33ms3rd
https://cdnjs.cloudflare.com/ajax/libs/react/18.3.1/umd/react.production.min.js768ms725ms2ms3rd
Unattributable689ms143ms0ms3rd
https://www.glassdoor.fr/seo-pages/assets/_next/static/chunks/framework-05d6d0fa5babb409.js640ms549ms28ms3rd
https://www.glassdoor.fr/index.htm?countryRedirect=true502ms54ms8ms3rd
https://www.glassdoor.fr/cdn-cgi/challenge-platform/scripts/jsd/main.js330ms305ms3ms3rd
https://www.glassdoor.fr/sam-global-nav/static/lib-676dc54385ec3c2f.min.js315ms158ms151ms3rd
https://www.glassdoor.fr/seo-pages/assets/_next/static/chunks/pages/_app-433206efb3eb5f16.js274ms99ms169ms3rd
https://www.glassdoor.fr/seo-pages/assets/_next/static/chunks/pages/index-f843b0dd771b3bdd.js201ms199ms1ms3rd

Showing top 10 of 16 scripts

F
JS Bundles
Action
51 scripts, 1.2 MB unused
FIX
51 scripts, 1.2 MB unused
Warning::
https://www.glassdoor.fr/sam-global-nav/static/lib...: 314 KB unused (83%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.glassdoor.fr/seo-pages/assets/_next/st...: 253 KB unused (83%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.glassdoor.fr/app-install-sam-server/st...: 105 KB unused (72%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.glassdoor.fr/user-login-sam-server/sta...: 94 KB unused (61%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://accounts.google.com/gsi/client: 70 KB unused (76%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 1.2 MB
1184 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.glassdoor.fr/sam-global-nav/static/lib-676dc54385ec3c2f.min.js381 KB314 KB (83%)✓3rd
https://www.glassdoor.fr/seo-pages/assets/_next/static/chunks/pages/_app-433206efb3eb5f16.js308 KB253 KB (83%)✓3rd
https://www.glassdoor.fr/app-install-sam-server/static/appInstall-a2b6550d2d15c7ad.min.js146 KB105 KB (72%)✓3rd
https://www.glassdoor.fr/user-login-sam-server/static/unifiedUserAuth-c1eefac054d37abd.min.js155 KB94 KB (61%)✓3rd
https://accounts.google.com/gsi/client93 KB70 KB (76%)✓3rd
https://www.glassdoor.fr/seo-pages/assets/_next/static/chunks/58474bfb-888746acbc80cc94.js98 KB69 KB (71%)✓3rd
https://www.glassdoor.fr/user-registration-sam/static/legacy/gd-user-onboarding.bundle.c36e78603cb1670a.js?v=5e67a90 KB68 KB (76%)✓3rd
https://www.glassdoor.fr/seo-pages/assets/_next/static/chunks/9548-97192ff5cb9cda4f.js90 KB64 KB (71%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-PST2JZ&l=gdGlobals160 KB58 KB (36%)✓3rd
https://www.glassdoor.fr/seo-pages/assets/_next/static/chunks/main-f8105bf919627e86.js41 KB23 KB (55%)✓3rd

Consider code splitting or tree shaking to reduce unused code.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

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.

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+
Image Optimization
6 images, 0 KB saveable
PASS
6 images, 0 KB saveable
Info::
All images are well-optimized
6 images 528 KB
0 oversized -0 KB
1 legacy format
0 missing dimensions CLS risk
A+
Font Loading
3 fonts (139 KB)
PASS
3 fonts (139 KB)
Info::
3 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

3

139 KB total

Render-blocking

0

of 3

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 2.0 s 4.0 s 6.0 s 8.0 s 10.0 s FCP 2.4 s LCP 10.9 shttps://www.glassdoor.com/assets/fonts/GlassdoorSans-Regular.woff2?v=20240110GlassdoorSans-Regular.w... https://www.glassdoor.com/assets/fonts/GlassdoorSans-Regular.woff2?v=20240110 — 44.6 KiB — 0 ms — font-display: swaphttps://www.glassdoor.com/assets/fonts/GlassdoorSans-Extrabold.woff2?v=20240110GlassdoorSans-Extrabold... https://www.glassdoor.com/assets/fonts/GlassdoorSans-Extrabold.woff2?v=20240110 — 46.7 KiB — 0 ms — font-display: swaphttps://www.glassdoor.com/assets/fonts/GlassdoorSans-Semibold.woff2?v=20240110GlassdoorSans-Semibold.... https://www.glassdoor.com/assets/fonts/GlassdoorSans-Semibold.woff2?v=20240110 — 47.7 KiB — 0 ms — font-display: swap
GlassdoorSans-Regular.w... woff2 swap
Size 45 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
GlassdoorSans-Extrabold... woff2 swap
Size 47 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
GlassdoorSans-Semibold.... woff2 swap
Size 48 KB
Load time 0 ms
Start 0 ms
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+
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
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Network Waterfall
90 requests over 0ms
INFO

Performance analysis not available for this result.

Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
100% of JavaScript execution is third-party
First-party Third-party 7249ms · 1601KB · €79/mo
Google Tag Manager
Tag Manager
Costly
Execution 1564ms
Transfer 160 KB
Unused 36%
Monthly Cost €17/mo
cdn.rudderlabs.com
Other
Costly
Execution 1249ms
Transfer 53 KB
Unused 42%
Monthly Cost €14/mo
cdnjs
CDN
Costly
Execution 768ms
Transfer 4 KB
Monthly Cost €8/mo
Unattributable
Other
Costly
Execution 689ms
Transfer 0 KB
Monthly Cost €7/mo
www.glassdoor.fr
Other
Costly
Execution 640ms
Transfer 59 KB
Unused 36%
Monthly Cost €7/mo
www.glassdoor.fr
Other
Costly
Execution 502ms
Transfer 62 KB
Monthly Cost €5/mo
www.glassdoor.fr
Other
Costly
Execution 330ms
Transfer 0 KB
Monthly Cost €4/mo
www.glassdoor.fr
Other
Costly
Execution 315ms
Transfer 381 KB
Unused 83%
Monthly Cost €3/mo
www.glassdoor.fr
Other
Costly
Execution 274ms
Transfer 308 KB
Unused 83%
Monthly Cost €3/mo
www.glassdoor.fr
Other
Costly
Execution 201ms
Transfer 5 KB
Monthly Cost €2/mo
www.glassdoor.fr
Other
Optional
Execution 154ms
Transfer 146 KB
Unused 72%
Monthly Cost €2/mo
www.glassdoor.fr
Other
Optional
Execution 141ms
Transfer 41 KB
Unused 55%
Monthly Cost €2/mo
www.glassdoor.fr
Other
Optional
Execution 131ms
Transfer 155 KB
Unused 61%
Monthly Cost €1/mo
www.glassdoor.fr
Other
Optional
Execution 128ms
Transfer 90 KB
Unused 76%
Monthly Cost €1/mo
www.glassdoor.fr
Other
Optional
Execution 88ms
Transfer 43 KB
Unused 52%
Monthly Cost €1/mo
accounts.google.com
Other
Optional
Execution 75ms
Transfer 93 KB
Unused 76%
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • Google Tag Manager adds 1564ms and costs ~€17/month
  • cdn.rudderlabs.com adds 1249ms and costs ~€14/month
  • cdnjs adds 768ms and costs ~€8/month
  • Unattributable adds 689ms and costs ~€7/month
  • www.glassdoor.fr adds 640ms and costs ~€7/month
  • www.glassdoor.fr adds 502ms and costs ~€5/month
  • www.glassdoor.fr adds 330ms and costs ~€4/month
  • www.glassdoor.fr adds 315ms and costs ~€3/month
  • www.glassdoor.fr adds 274ms and costs ~€3/month
  • www.glassdoor.fr adds 201ms and costs ~€2/month

100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.

Why this matters

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

Google Tag Manager takes 1564ms 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

cdn.rudderlabs.com takes 1249ms 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

cdnjs takes 768ms 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

Unattributable takes 689ms 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

www.glassdoor.fr takes 640ms 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

www.glassdoor.fr takes 502ms 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

www.glassdoor.fr takes 330ms 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

www.glassdoor.fr takes 315ms 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

83% of www.glassdoor.fr's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

www.glassdoor.fr takes 274ms 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

83% of www.glassdoor.fr's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

www.glassdoor.fr takes 201ms 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

72% of www.glassdoor.fr's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

55% of www.glassdoor.fr's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

61% of www.glassdoor.fr's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

76% of www.glassdoor.fr's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

52% of www.glassdoor.fr's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

76% of accounts.google.com's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

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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