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https://slideserve.com

Performance

· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
88
GRADE
B
FIX
2
REVIEW
3
PASS
8
INFO
2

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

Mobile Desktop
92
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
95
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
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.

992 ms

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

1.65 s

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.

0.004

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

992 ms

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

1.65 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
15
8 PASS 3 REVIEW 2 FIX
D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (944.8 KiB of 944.9 KiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
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
Image Optimization
8 images, 0 KB saveable
REVIEW
8 images, 0 KB saveable
Warning::
https://www.slideserve.com/img/preload-bg.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
8 images 521 KB
0 oversized -0 KB
6 legacy format
1 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

B
JS Bundles
3 scripts, 65 KB unused
REVIEW
3 scripts, 65 KB unused
Warning::
https://www.googletagmanager.com/gtag/js?id=G-534B...: 65 KB unused (41%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 65 KB
65 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtag/js?id=G-534BDNWH21157 KB65 KB (41%)✓3rd
https://www.slideserve.com/assets/vendor/bootstrap/js/bootstrap.bundle.min.js24 KB—✓3rd
https://www.slideserve.com/assets/js/jquery.3.7.0.min.js30 KB—✓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

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A
Page Weight Budget
945 KB transferred, 22 requests
PASS
945 KB transferred, 22 requests
Info::
Page weighs 1.6 MB (945 KB transferred)
Info::
22 HTTP requests
Info::
Estimated 0.19 g CO2 per page load
945 KB / 2.4 MB budget
945 KB transferred
22 requests
0.19 g CO2 per page load
Images 521.4 KiB 55%
JavaScript 210.2 KiB 22%
Other 105.3 KiB 11%
Fonts 55.6 KiB 6%
CSS 33.8 KiB 4%
HTML 17.7 KiB 2%
Other 551 B 0%
Other 329 B 0%
0 2.4 MB 4.9 MB
Under budget
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+
JS Execution Cost
248ms total JS execution
PASS
248ms total JS execution
Info::
https://www.slideserve.com/: 129ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-534B...: 68ms CPU time
Info::
Unattributable: 51ms CPU time
Warning::
Third-party scripts: 248ms (100% of total)

Main Thread Breakdown

Style & Layout 32% Script Evaluation 29% Other 21% Rendering 9% Script Parsing & Compilation 6%
ScriptTotalScriptingParse/CompileParty
https://www.slideserve.com/129ms7ms1ms3rd
https://www.googletagmanager.com/gtag/js?id=G-534BDNWH2168ms56ms12ms3rd
Unattributable51ms2ms0ms3rd
A+
Font Loading
2 fonts (56 KB)
PASS
2 fonts (56 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

56 KB total

Render-blocking

0

of 2

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s 1.5 s FCP 992 ms LCP 1.6 shttps://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2memvYaGs126MiZpBA-UvWbX... https://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2 — 42.0 KiB — 60 ms — font-display: swaphttps://fonts.gstatic.com/s/robotoslab/v36/BngbUXZYTXPIvIBgJJSb6s3BzlRRfKOFbvjojISmb2RjV9Su1cai.woff2BngbUXZYTXPIvIBgJJSb6s3... https://fonts.gstatic.com/s/robotoslab/v36/BngbUXZYTXPIvIBgJJSb6s3BzlRRfKOFbvjojISmb2RjV9Su1cai.woff2 — 13.6 KiB — 39 ms — font-display: swap
memvYaGs126MiZpBA-UvWbX... woff2 swap
Size 42 KB
Load time 60 ms
Start 839 ms
Risk FOUT — text flashes from fallback to web font
BngbUXZYTXPIvIBgJJSb6s3... woff2 swap
Size 14 KB
Load time 39 ms
Start 840 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
Page Weight Inventory
22 resources · 945 KB · 65 KB savings available
PASS
22 resources · 945 KB · 65 KB savings available
Info::
Within 1MB page-weight target
Got: 945 KB
Info::
~65 KB of savings available
Warning::
21 third-party resources (100% of weight)
22 resources · 944.9 KiB · 21 third-party Within 1MB page-weight target
Image 66% · 626.6 KiB
JavaScript 22% · 210.2 KiB
Font 6% · 55.6 KiB
CSS 4% · 33.8 KiB
Document 2% · 18.1 KiB
Other 0% · 551 B

~64.7 KiB of savings available

Remove unused JavaScript: 64.7 KiB
Network Waterfall
22 requests over 1475ms
INFO
0 ms 500 ms 1.0 s 1.5 s FCP 992 ms LCP 1.6 shttps://slideserve.com// https://slideserve.com/ — 301 — 87 B — 516 ms — h2https://www.slideserve.com/www.slideserve.com/ https://www.slideserve.com/ — 200 — 17.7 KiB — 173 ms — h2https://www.slideserve.com/assets/vendor/bootstrap/css/bootstrap.min.css?v=1.0www.slideserve.com/assets/vendor/bo... https://www.slideserve.com/assets/vendor/bootstrap/css/bootstrap.min.css?v=1.0 — 200 — 30.5 KiB — 7 ms — h2https://cdn9.slideserve.com/14784023/grammy-awards-2026-fashion-moments-winners-n.jpgcdn9.slideserve.com/14784023/grammy... https://cdn9.slideserve.com/14784023/grammy-awards-2026-fashion-moments-winners-n.jpg — 200 — 141.5 KiB — 32 ms — h2https://www.slideserve.com/assets/img/logo.svgwww.slideserve.com/assets/img/logo.... https://www.slideserve.com/assets/img/logo.svg — 200 — 7.7 KiB — 3 ms — h2https://cdn9.slideserve.com/14765704/greenland-an-island-of-ice-n.jpgcdn9.slideserve.com/14765704/greenl... https://cdn9.slideserve.com/14765704/greenland-an-island-of-ice-n.jpg — 200 — 119.3 KiB — 30 ms — h2https://cdn9.slideserve.com/14761860/fire-purified-horses-n.jpgcdn9.slideserve.com/14761860/fire-p... https://cdn9.slideserve.com/14761860/fire-purified-horses-n.jpg — 200 — 161.7 KiB — 30 ms — h2https://fonts.googleapis.com/css2?family=Roboto+Slab:wght@400;700&display=swapfonts.googleapis.com/css2?family=Ro... https://fonts.googleapis.com/css2?family=Roboto+Slab:wght@400;700&display=swap — 200 — 1.1 KiB — 93 ms — h2https://www.slideserve.com/assets/vendor/bootstrap/js/bootstrap.bundle.min.jswww.slideserve.com/assets/vendor/bo... https://www.slideserve.com/assets/vendor/bootstrap/js/bootstrap.bundle.min.js — 200 — 23.5 KiB — 12 ms — h3https://fonts.googleapis.com/css?family=Open+Sans:400,400i,600,700%7CRoboto+Slab&display=swapfonts.googleapis.com/css?family=Ope... https://fonts.googleapis.com/css?family=Open+Sans:400,400i,600,700%7CRoboto+Slab&display=swap — 200 — 2.1 KiB — 94 ms — h2https://www.googletagmanager.com/gtag/js?id=G-534BDNWH21www.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=G-534BDNWH21 — 200 — 156.7 KiB — 181 ms — h2https://www.slideserve.com/assets/js/jquery.3.7.0.min.jswww.slideserve.com/assets/js/jquery... https://www.slideserve.com/assets/js/jquery.3.7.0.min.js — 200 — 30.0 KiB — 13 ms — h3data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='18' height='18' v…www.w3.org/2000/svg' width='18' hei... data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='18' height='18' v… — 200 — 0 B — 0 ms — datadata:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='18' height='18' v…www.w3.org/2000/svg' width='18' hei... data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='18' height='18' v… — 200 — 0 B — 0 ms — datahttps://www.slideserve.com/img/banner_home.webpwww.slideserve.com/img/banner_home.... https://www.slideserve.com/img/banner_home.webp — 200 — 89.9 KiB — 9 ms — h3https://www.slideserve.com/img/preload-bg.svgwww.slideserve.com/img/preload-bg.s... https://www.slideserve.com/img/preload-bg.svg — 200 — 730 B — 5 ms — h3https://www.slideserve.com/assets/img/preload-bg.svgwww.slideserve.com/assets/img/prelo... https://www.slideserve.com/assets/img/preload-bg.svg — 200 — 730 B — 4 ms — h3https://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2fonts.gstatic.com/s/opensans/v44/me... https://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2 — 200 — 42.0 KiB — 60 ms — h3https://fonts.gstatic.com/s/robotoslab/v36/BngbUXZYTXPIvIBgJJSb6s3BzlRRfKOFbvjojISmb2RjV9Su1cai.woff2fonts.gstatic.com/s/robotoslab/v36/... https://fonts.gstatic.com/s/robotoslab/v36/BngbUXZYTXPIvIBgJJSb6s3BzlRRfKOFbvjojISmb2RjV9Su1cai.woff2 — 200 — 13.6 KiB — 39 ms — h3https://www.slideserve.com/ajax/auth-state.php?type=dropdownwww.slideserve.com/ajax/auth-state.... https://www.slideserve.com/ajax/auth-state.php?type=dropdown — 200 — 329 B — 615 ms — h3https://region1.google-analytics.com/g/collect?v=2&tid=G-534BDNWH21&gtm=45je64k0v9103640646za200zd9103640646&_p=1776892930359&gcd=13l3lPl2l1l1&npa=1&dma_cps=a&dma=1&are=1&cid=1655155072.1776892931&frm=0&pscdl=noapi&rcb=19&sr=800x600&uaa=x86&uab=64&uafvl=Chromium%3B147.0.7727.101%7CNot.A%252FBrand%3B8.0.0.0&uam=&uamb=0&uap=macOS&uapv=10.15.7&uaw=0&ul=en-us&_s=1&tag_exp=0~115938466~115938469~117266400~117512542~117884344~118463262&sid=1776892930&sct=1&seg=0&dl=https%3A%2F%2Fwww.slideserve.com%2F&dt=Upload%20and%20Share%20Documents%20Presentations%20Online%20-%20SlideServe&en=page_view&_fv=1&_nsi=1&_ss=1&_ee=1&tfd=993region1.google-analytics.com/g/coll... https://region1.google-analytics.com/g/collect?v=2&tid=G-534BDNWH21&gtm=45je64k0v9103640646za200zd9103640646&_p=1776892930359&gcd=13l3lPl2l1l1&npa=1&dma_cps=a&dma=1&are=1&cid=1655155072.1776892931&frm=0&pscdl=noapi&rcb=19&sr=800x600&uaa=x86&uab=64&uafvl=Chromium%3B147.0.7727.101%7CNot.A%252FBrand%3B8.0.0.0&uam=&uamb=0&uap=macOS&uapv=10.15.7&uaw=0&ul=en-us&_s=1&tag_exp=0~115938466~115938469~117266400~117512542~117884344~118463262&sid=1776892930&sct=1&seg=0&dl=https%3A%2F%2Fwww.slideserve.com%2F&dt=Upload%20and%20Share%20Documents%20Presentations%20Online%20-%20SlideServe&en=page_view&_fv=1&_nsi=1&_ss=1&_ee=1&tfd=993 — 204 — 551 B — 83 ms — h2https://www.slideserve.com/favicon.icowww.slideserve.com/favicon.ico https://www.slideserve.com/favicon.ico — 200 — 105.2 KiB — 4 ms — h3
HTML JavaScript CSS Images Fonts XHR/Fetch Other
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 248ms · 174KB · €3/mo
www.slideserve.com
Other
Optional
Execution 129ms
Transfer 18 KB
Monthly Cost €1/mo
Google Tag Manager
Tag Manager
Optional
Execution 68ms
Transfer 157 KB
Unused 41%
Monthly Cost €1/mo
Unattributable
Other
Optional
Execution 51ms
Transfer 0 KB
Monthly Cost €1/mo

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

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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