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https://wikipedia.org

Performance

· 22 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
90
GRADE
A
FIX
2
REVIEW
4
PASS
13
INFO
3

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

Mobile Desktop
100
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.
100
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.

625 ms

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

625 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.

0.000

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

625 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.

625 ms

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
22
13 PASS 4 REVIEW 2 FIX
D
Third-Party Impact
Action
98% third-party, 0 ms blocking
FIX
98% third-party, 0 ms blocking
Warning::
Third-party code accounts for 98% of page weight (78.5 KiB of 79.7 KiB)
Info::
Third-party blocking time is low (0 ms)
98%
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
HTTP/3 (QUIC)
HTTP/3 not advertised
REVIEW
HTTP/3 not advertised
Info::
HTTP/3 (QUIC) is not advertised
HTTP/3 isn't advertised via Alt-Svc and the worker didn't negotiate h3. HTTP/3 reduces handshake latency (1-RTT instead of 2-3 RTTs) and is more resilient on lossy connections. Most modern CDNs (Cloudflare, Fastly, AWS CloudFront, Google Cloud CDN) support HTTP/3 with a single config switch -- consider enabling for mobile-heavy workloads.
C
Compression Algorithm
Action
Main response served uncompressed
REVIEW
Main response served uncompressed
Info::
Main HTML response has no Content-Encoding (uncompressed)
The main HTML document is served without compression. The Text Compression section above lists the broader picture; for the main response specifically, even gzip would shave ~70-80% off most text payloads.
B
Main HTML Cache-Control
No Cache-Control header on main HTML response
REVIEW
No Cache-Control header on main HTML response
Info::
Main HTML response has no Cache-Control header
Without an explicit Cache-Control, browsers fall back to heuristic caching (~10% of Last-Modified age). Set `Cache-Control: no-cache` or `max-age=300` for HTML to control freshness explicitly -- prevents stale auth state and SPA shell drift.
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Page Weight Budget
80 KB transferred, 7 requests
PASS
80 KB transferred, 7 requests
Info::
Page weighs 210 KB (80 KB transferred)
Info::
7 HTTP requests
Info::
Estimated 0.02 g CO2 per page load
80 KB / 2.4 MB budget
80 KB transferred
7 requests
0.02 g CO2 per page load
Images 35.0 KiB 44%
HTML 31.0 KiB 39%
JavaScript 10.6 KiB 13%
Other 3.1 KiB 4%
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
Image Optimization
2 images, 0 KB saveable
PASS
2 images, 0 KB saveable
Info::
All images are well-optimized
2 images 35 KB
0 oversized -0 KB
2 legacy format
0 missing dimensions CLS risk
A+
JS Execution Cost
171ms total JS execution
PASS
171ms total JS execution
Info::
https://www.wikipedia.org/: 171ms CPU time
Warning::
Third-party scripts: 171ms (100% of total)

Main Thread Breakdown

Style & Layout 68% Other 18% Script Evaluation 6% Parse HTML & CSS 4% Rendering 4%
ScriptTotalScriptingParse/CompileParty
https://www.wikipedia.org/171ms3ms1ms3rd
A+
Font Loading
No web fonts (system fonts)
PASS
No web fonts (system fonts)
Info::
No web fonts loaded — system fonts are fastest
No web fonts loaded — system fonts are optimal.
A+
JS Bundles
2 scripts, 0 KB unused
PASS
2 scripts, 0 KB unused
0 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.wikipedia.org/portal/wikipedia.org/assets/js/index-34f340e24a.js9 KB—✓3rd
https://www.wikipedia.org/portal/wikipedia.org/assets/js/gt-ie9-507b16b6be.js1 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+
LCP Image Preload
LCP preload audit not available
PASS
LCP preload audit not available
Info::
LCP image preload audit not available for this scan
A+
Server-Timing Observability
2 Server-Timing entries advertised
PASS
2 Server-Timing entries advertised
Info::
Server-Timing header advertises 2 timing entries
A+
Server Response Intelligence
2 server-response signal(s) detected
PASS
2 server-response signal(s) detected
Info::
`Vary` header declared: X-Forwarded-Proto
The page declares a `Vary` header, telling downstream caches which request headers the response varies on. Critical for content-negotiated responses (compression, language, cookies, device class).
Info::
No `ETag` or `Last-Modified` -- conditional GET not supported
Without either header, browsers can't issue conditional GETs and refresh always re-downloads the full response body even when nothing changed. Add `ETag: "<hash>"` (or `Last-Modified: <date>`) on cacheable responses; the server returns 304 Not Modified when the client's cached copy is still valid, saving bandwidth.
A
Page Weight Inventory
7 resources · 80 KB · 0 KB savings available
PASS
7 resources · 80 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 80 KB
Warning::
6 third-party resources (98% of weight)
7 resources · 79.7 KiB · 6 third-party Within 1MB page-weight target
Image 46% · 36.8 KiB
Document 41% · 32.3 KiB
JavaScript 13% · 10.6 KiB
Network Waterfall
7 requests over 363ms
INFO
0 ms 200 ms 400 ms 600 ms FCP 625 ms LCP 625 mshttps://wikipedia.org// https://wikipedia.org/ — 301 — 1.3 KiB — 85 ms — h2https://www.wikipedia.org/www.wikipedia.org/ https://www.wikipedia.org/ — 200 — 31.0 KiB — 55 ms — h2https://www.wikipedia.org/portal/wikipedia.org/assets/img/Wikipedia-logo-v2.pngwww.wikipedia.org/portal/wikipedia.... https://www.wikipedia.org/portal/wikipedia.org/assets/img/Wikipedia-logo-v2.png — 200 — 16.3 KiB — 33 ms — h2https://www.wikipedia.org/portal/wikipedia.org/assets/js/index-34f340e24a.jswww.wikipedia.org/portal/wikipedia.... https://www.wikipedia.org/portal/wikipedia.org/assets/js/index-34f340e24a.js — 200 — 9.2 KiB — 37 ms — h2https://www.wikipedia.org/portal/wikipedia.org/assets/js/gt-ie9-507b16b6be.jswww.wikipedia.org/portal/wikipedia.... https://www.wikipedia.org/portal/wikipedia.org/assets/js/gt-ie9-507b16b6be.js — 200 — 1.4 KiB — 38 ms — h2https://www.wikipedia.org/portal/wikipedia.org/assets/img/sprite-e49fbf32.svgwww.wikipedia.org/portal/wikipedia.... https://www.wikipedia.org/portal/wikipedia.org/assets/img/sprite-e49fbf32.svg — 200 — 18.7 KiB — 37 ms — h2https://www.wikipedia.org/static/favicon/wikipedia.icowww.wikipedia.org/static/favicon/wi... https://www.wikipedia.org/static/favicon/wikipedia.ico — 200 — 1.9 KiB — 30 ms — h2
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 171ms · 31KB · $2/mo
www.wikipedia.org
Other
Optional
Execution 171ms
Transfer 31 KB
Monthly Cost $2/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

Image Optimization
1 images, 15 KB total, 0 KB wasted
INFO

Image Optimization Audit

Total Images

1

Total Size

15 KB

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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