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Performance

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

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

Mobile Desktop
74
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
76
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.
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.

1.51 s

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

1.68 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.

0.258

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

1.51 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.

1.68 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
9 PASS 2 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 (536.9 KiB of 537.2 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
JS Bundles
10 scripts, 118 KB unused
REVIEW
10 scripts, 118 KB unused
Warning::
https://ajax.googleapis.com/ajax/libs/jqueryui/1.1...: 59 KB unused (89%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://ajax.googleapis.com/ajax/libs/jqueryui/1.1...: 59 KB unused (89%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 118 KB
118 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.js66 KB59 KB (89%)✓3rd
https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.js0 KB59 KB (89%)✓3rd
https://analytics.python.org/js/script.file-downloads.outbound-links.js2 KB—✓3rd
https://media.ethicalads.io/media/client/v1.4.0/ethicalads.min.js9 KB—✓3rd
https://www.python.org/static/js/libs/modernizr.js5 KB—✓3rd
https://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js33 KB—✓3rd
https://www.python.org/static/js/libs/masonry.pkgd.min.js8 KB—✓3rd
https://www.python.org/static/js/libs/html-includes.js0 KB—✓3rd
https://www.python.org/static/js/main-min.e1f3949ae225.js10 KB—✗3rd
https://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js0 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

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
537 KB transferred, 37 requests
PASS
537 KB transferred, 37 requests
Info::
Page weighs 1.2 MB (537 KB transferred)
Info::
37 HTTP requests
Info::
Estimated 0.11 g CO2 per page load
537 KB / 2.4 MB budget
537 KB transferred
37 requests
0.11 g CO2 per page load
CSS 156.1 KiB 29%
Fonts 149.6 KiB 28%
JavaScript 133.2 KiB 25%
HTML 48.8 KiB 9%
Images 28.5 KiB 5%
Other 15.2 KiB 3%
Other 5.5 KiB 1%
Other 297 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
Image Optimization
2 images, 0 KB saveable
PASS
2 images, 0 KB saveable
Info::
All images are well-optimized
2 images 29 KB
0 oversized -0 KB
2 legacy format
0 missing dimensions CLS risk
A+
JS Execution Cost
156ms total JS execution
PASS
156ms total JS execution
Info::
https://www.python.org/: 96ms CPU time
Info::
https://ajax.googleapis.com/ajax/libs/jquery/1.8.2...: 60ms CPU time
Warning::
Third-party scripts: 156ms (100% of total)

Main Thread Breakdown

Style & Layout 31% Script Evaluation 28% Other 26% Rendering 5% Script Parsing & Compilation 5% Parse HTML & CSS 5%
ScriptTotalScriptingParse/CompileParty
https://www.python.org/96ms1ms0ms3rd
https://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js60ms40ms2ms3rd
A+
Font Loading
6 fonts (150 KB)
PASS
6 fonts (150 KB)
Info::
6 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

6

150 KB total

Render-blocking

0

of 6

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 1.5 s LCP 1.7 sdata:application/x-font-woff;charset=utf-8;base64,d09GRgABAAAAADDwAAsAAAAAMKQAAQAAAAAAAAAAAAAAAAAAA…x-font-woff;charset=utf... data:application/x-font-woff;charset=utf-8;base64,d09GRgABAAAAADDwAAsAAAAAMKQAAQAAAAAAAAAAAAAAAAAAA… — 12.2 KiB — 41 ms — font-display: swaphttps://www.python.org/static/fonts/SourceSansPro-Regular-webfont.fd0d51605201.woffSourceSansPro-Regular-w... https://www.python.org/static/fonts/SourceSansPro-Regular-webfont.fd0d51605201.woff — 26.1 KiB — 8 ms — font-display: swaphttps://www.python.org/static/fonts/FluxRegular.f5549a4fe75f.woffFluxRegular.f5549a4fe75... https://www.python.org/static/fonts/FluxRegular.f5549a4fe75f.woff — 29.5 KiB — 8 ms — font-display: swaphttps://www.python.org/static/fonts/SourceSansPro-Bold-webfont.be855452e565.woffSourceSansPro-Bold-webf... https://www.python.org/static/fonts/SourceSansPro-Bold-webfont.be855452e565.woff — 25.8 KiB — 8 ms — font-display: swaphttps://www.python.org/static/fonts/SourceSansPro-It-webfont.1aa29ac0f190.woffSourceSansPro-It-webfon... https://www.python.org/static/fonts/SourceSansPro-It-webfont.1aa29ac0f190.woff — 27.5 KiB — 8 ms — font-display: swaphttps://www.python.org/static/fonts/FluxBold.3fd71a747d5c.woffFluxBold.3fd71a747d5c.woff https://www.python.org/static/fonts/FluxBold.3fd71a747d5c.woff — 28.6 KiB — 8 ms — font-display: swap
x-font-woff;charset=utf... woff swap
Size 12 KB
Load time 41 ms
Start 616 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
SourceSansPro-Regular-w... woff swap
Size 26 KB
Load time 8 ms
Start 658 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
FluxRegular.f5549a4fe75... woff swap
Size 29 KB
Load time 8 ms
Start 658 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
SourceSansPro-Bold-webf... woff swap
Size 26 KB
Load time 8 ms
Start 659 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
SourceSansPro-It-webfon... woff swap
Size 27 KB
Load time 8 ms
Start 659 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
FluxBold.3fd71a747d5c.woff woff swap
Size 29 KB
Load time 8 ms
Start 659 ms
Risk FOUT — text flashes from fallback to web font
  • 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 ~45 KB and ~90 ms

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
37 resources · 537 KB · 118 KB savings available
PASS
37 resources · 537 KB · 118 KB savings available
Info::
Within 1MB page-weight target
Got: 537 KB
Info::
~118 KB of savings available
Warning::
36 third-party resources (100% of weight)
37 resources · 537.2 KiB · 36 third-party Within 1MB page-weight target
CSS 29% · 156.1 KiB
Font 28% · 149.6 KiB
JavaScript 25% · 133.2 KiB
Document 10% · 53.1 KiB
Image 8% · 43.4 KiB
Other 0% · 1.7 KiB

~118.3 KiB of savings available

Remove unused JavaScript: 118.3 KiB
Network Waterfall
37 requests over 1141ms
INFO
0 ms 500 ms 1.0 s 1.5 s FCP 1.5 s LCP 1.7 shttps://python.ca// https://python.ca/ — 302 — 247 B — 478 ms — http/1.1http://www.python.org/www.python.org/ http://www.python.org/ — 307 — 0 B — 0 ms — http/1.1https://www.python.org/www.python.org/ https://www.python.org/ — 200 — 48.8 KiB — 36 ms — h2https://analytics.python.org/js/script.file-downloads.outbound-links.jsanalytics.python.org/js/script.file... https://analytics.python.org/js/script.file-downloads.outbound-links.js — 200 — 1.8 KiB — 17 ms — h2https://media.ethicalads.io/media/client/v1.4.0/ethicalads.min.jsmedia.ethicalads.io/media/client/v1... https://media.ethicalads.io/media/client/v1.4.0/ethicalads.min.js — 200 — 8.7 KiB — 75 ms — h2https://www.python.org/static/js/libs/modernizr.jswww.python.org/static/js/libs/moder... https://www.python.org/static/js/libs/modernizr.js — 200 — 5.1 KiB — 13 ms — h2https://www.python.org/static/stylesheets/style.c4f369bed0d3.csswww.python.org/static/stylesheets/s... https://www.python.org/static/stylesheets/style.c4f369bed0d3.css — 200 — 122.7 KiB — 21 ms — h2https://www.python.org/static/stylesheets/mq.a4feecea96fa.csswww.python.org/static/stylesheets/m... https://www.python.org/static/stylesheets/mq.a4feecea96fa.css — 200 — 17.4 KiB — 18 ms — h2https://www.python.org/static/stylesheets/font-awesome.bf0c425cdb73.csswww.python.org/static/stylesheets/f... https://www.python.org/static/stylesheets/font-awesome.bf0c425cdb73.css — 200 — 7.1 KiB — 12 ms — h2https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/themes/smoothness/jquery-ui.cssajax.googleapis.com/ajax/libs/jquer... https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/themes/smoothness/jquery-ui.css — 200 — 8.8 KiB — 77 ms — h2https://www.python.org/static/img/python-logo.pngwww.python.org/static/img/python-lo... https://www.python.org/static/img/python-logo.png — 200 — 15.6 KiB — 12 ms — h2https://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.jsajax.googleapis.com/ajax/libs/jquer... https://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js — 200 — 33.0 KiB — 103 ms — h2https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.jsajax.googleapis.com/ajax/libs/jquer... https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.js — 200 — 66.5 KiB — 112 ms — h2https://www.python.org/static/js/libs/masonry.pkgd.min.jswww.python.org/static/js/libs/mason... https://www.python.org/static/js/libs/masonry.pkgd.min.js — 200 — 8.0 KiB — 6 ms — h2https://www.python.org/static/js/libs/html-includes.jswww.python.org/static/js/libs/html-... https://www.python.org/static/js/libs/html-includes.js — 200 — 303 B — 5 ms — h2https://www.python.org/static/js/main-min.e1f3949ae225.jswww.python.org/static/js/main-min.e... https://www.python.org/static/js/main-min.e1f3949ae225.js — 200 — 9.9 KiB — 6 ms — h2https://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.jsajax.googleapis.com/ajax/libs/jquer... https://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js — 200 — 0 B — 62 ms — h2https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.jsajax.googleapis.com/ajax/libs/jquer... https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.js — 200 — 0 B — 85 ms — h2https://www.python.org/static/img/python-logo-large.c36dccadd999.png?1694722768www.python.org/static/img/python-lo... https://www.python.org/static/img/python-logo-large.c36dccadd999.png?1694722768 — 200 — 13.0 KiB — 2 ms — h2data:application/x-font-woff;charset=utf-8;base64,d09GRgABAAAAADDwAAsAAAAAMKQAAQAAAAAAAAAAAAAAAAAAA…data:application/x-font-woff;charse... data:application/x-font-woff;charset=utf-8;base64,d09GRgABAAAAADDwAAsAAAAAMKQAAQAAAAAAAAAAAAAAAAAAA… — 200 — 12.2 KiB — 41 ms — datahttps://www.python.org/static/fonts/SourceSansPro-Regular-webfont.fd0d51605201.woffwww.python.org/static/fonts/SourceS... https://www.python.org/static/fonts/SourceSansPro-Regular-webfont.fd0d51605201.woff — 200 — 26.1 KiB — 8 ms — h2https://www.python.org/static/fonts/FluxRegular.f5549a4fe75f.woffwww.python.org/static/fonts/FluxReg... https://www.python.org/static/fonts/FluxRegular.f5549a4fe75f.woff — 200 — 29.5 KiB — 8 ms — h2https://www.python.org/static/fonts/SourceSansPro-Bold-webfont.be855452e565.woffwww.python.org/static/fonts/SourceS... https://www.python.org/static/fonts/SourceSansPro-Bold-webfont.be855452e565.woff — 200 — 25.8 KiB — 8 ms — h2https://www.python.org/static/fonts/SourceSansPro-It-webfont.1aa29ac0f190.woffwww.python.org/static/fonts/SourceS... https://www.python.org/static/fonts/SourceSansPro-It-webfont.1aa29ac0f190.woff — 200 — 27.5 KiB — 8 ms — h2https://www.python.org/static/fonts/FluxBold.3fd71a747d5c.woffwww.python.org/static/fonts/FluxBol... https://www.python.org/static/fonts/FluxBold.3fd71a747d5c.woff — 200 — 28.6 KiB — 8 ms — h2https://www.python.org/authenticatedwww.python.org/authenticated https://www.python.org/authenticated — 200 — 456 B — 2 ms — h2https://analytics.python.org/api/eventanalytics.python.org/api/event https://analytics.python.org/api/event — 202 — 297 B — 421 ms — h3https://console.python.org/python-dot-org-live-consoles-statusconsole.python.org/python-dot-org-l... https://console.python.org/python-dot-org-live-consoles-status — 200 — 248 B — 319 ms — h2https://2p66nmmycsj3.statuspage.io/api/v2/status.json2p66nmmycsj3.statuspage.io/api/v2/s... https://2p66nmmycsj3.statuspage.io/api/v2/status.json — 200 — 1.2 KiB — 128 ms — h2https://www.python.org/box/supernav-python-about/www.python.org/box/supernav-python-... https://www.python.org/box/supernav-python-about/ — 200 — 654 B — 4 ms — h2
0 ms 500 ms 1.0 s 1.5 s FCP 1.5 s LCP 1.7 shttps://python.ca// https://python.ca/ — 302 — 247 B — 478 ms — http/1.1http://www.python.org/www.python.org/ http://www.python.org/ — 307 — 0 B — 0 ms — http/1.1https://www.python.org/www.python.org/ https://www.python.org/ — 200 — 48.8 KiB — 36 ms — h2https://analytics.python.org/js/script.file-downloads.outbound-links.jsanalytics.python.org/js/script.file... https://analytics.python.org/js/script.file-downloads.outbound-links.js — 200 — 1.8 KiB — 17 ms — h2https://media.ethicalads.io/media/client/v1.4.0/ethicalads.min.jsmedia.ethicalads.io/media/client/v1... https://media.ethicalads.io/media/client/v1.4.0/ethicalads.min.js — 200 — 8.7 KiB — 75 ms — h2https://www.python.org/static/js/libs/modernizr.jswww.python.org/static/js/libs/moder... https://www.python.org/static/js/libs/modernizr.js — 200 — 5.1 KiB — 13 ms — h2https://www.python.org/static/stylesheets/style.c4f369bed0d3.csswww.python.org/static/stylesheets/s... https://www.python.org/static/stylesheets/style.c4f369bed0d3.css — 200 — 122.7 KiB — 21 ms — h2https://www.python.org/static/stylesheets/mq.a4feecea96fa.csswww.python.org/static/stylesheets/m... https://www.python.org/static/stylesheets/mq.a4feecea96fa.css — 200 — 17.4 KiB — 18 ms — h2https://www.python.org/static/stylesheets/font-awesome.bf0c425cdb73.csswww.python.org/static/stylesheets/f... https://www.python.org/static/stylesheets/font-awesome.bf0c425cdb73.css — 200 — 7.1 KiB — 12 ms — h2https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/themes/smoothness/jquery-ui.cssajax.googleapis.com/ajax/libs/jquer... https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/themes/smoothness/jquery-ui.css — 200 — 8.8 KiB — 77 ms — h2https://www.python.org/static/img/python-logo.pngwww.python.org/static/img/python-lo... https://www.python.org/static/img/python-logo.png — 200 — 15.6 KiB — 12 ms — h2https://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.jsajax.googleapis.com/ajax/libs/jquer... https://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js — 200 — 33.0 KiB — 103 ms — h2https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.jsajax.googleapis.com/ajax/libs/jquer... https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.js — 200 — 66.5 KiB — 112 ms — h2https://www.python.org/static/js/libs/masonry.pkgd.min.jswww.python.org/static/js/libs/mason... https://www.python.org/static/js/libs/masonry.pkgd.min.js — 200 — 8.0 KiB — 6 ms — h2https://www.python.org/static/js/libs/html-includes.jswww.python.org/static/js/libs/html-... https://www.python.org/static/js/libs/html-includes.js — 200 — 303 B — 5 ms — h2https://www.python.org/static/js/main-min.e1f3949ae225.jswww.python.org/static/js/main-min.e... https://www.python.org/static/js/main-min.e1f3949ae225.js — 200 — 9.9 KiB — 6 ms — h2https://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.jsajax.googleapis.com/ajax/libs/jquer... https://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js — 200 — 0 B — 62 ms — h2https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.jsajax.googleapis.com/ajax/libs/jquer... https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.js — 200 — 0 B — 85 ms — h2https://www.python.org/static/img/python-logo-large.c36dccadd999.png?1694722768www.python.org/static/img/python-lo... https://www.python.org/static/img/python-logo-large.c36dccadd999.png?1694722768 — 200 — 13.0 KiB — 2 ms — h2data:application/x-font-woff;charset=utf-8;base64,d09GRgABAAAAADDwAAsAAAAAMKQAAQAAAAAAAAAAAAAAAAAAA…data:application/x-font-woff;charse... data:application/x-font-woff;charset=utf-8;base64,d09GRgABAAAAADDwAAsAAAAAMKQAAQAAAAAAAAAAAAAAAAAAA… — 200 — 12.2 KiB — 41 ms — datahttps://www.python.org/static/fonts/SourceSansPro-Regular-webfont.fd0d51605201.woffwww.python.org/static/fonts/SourceS... https://www.python.org/static/fonts/SourceSansPro-Regular-webfont.fd0d51605201.woff — 200 — 26.1 KiB — 8 ms — h2https://www.python.org/static/fonts/FluxRegular.f5549a4fe75f.woffwww.python.org/static/fonts/FluxReg... https://www.python.org/static/fonts/FluxRegular.f5549a4fe75f.woff — 200 — 29.5 KiB — 8 ms — h2https://www.python.org/static/fonts/SourceSansPro-Bold-webfont.be855452e565.woffwww.python.org/static/fonts/SourceS... https://www.python.org/static/fonts/SourceSansPro-Bold-webfont.be855452e565.woff — 200 — 25.8 KiB — 8 ms — h2https://www.python.org/static/fonts/SourceSansPro-It-webfont.1aa29ac0f190.woffwww.python.org/static/fonts/SourceS... https://www.python.org/static/fonts/SourceSansPro-It-webfont.1aa29ac0f190.woff — 200 — 27.5 KiB — 8 ms — h2https://www.python.org/static/fonts/FluxBold.3fd71a747d5c.woffwww.python.org/static/fonts/FluxBol... https://www.python.org/static/fonts/FluxBold.3fd71a747d5c.woff — 200 — 28.6 KiB — 8 ms — h2https://www.python.org/authenticatedwww.python.org/authenticated https://www.python.org/authenticated — 200 — 456 B — 2 ms — h2https://analytics.python.org/api/eventanalytics.python.org/api/event https://analytics.python.org/api/event — 202 — 297 B — 421 ms — h3https://console.python.org/python-dot-org-live-consoles-statusconsole.python.org/python-dot-org-l... https://console.python.org/python-dot-org-live-consoles-status — 200 — 248 B — 319 ms — h2https://2p66nmmycsj3.statuspage.io/api/v2/status.json2p66nmmycsj3.statuspage.io/api/v2/s... https://2p66nmmycsj3.statuspage.io/api/v2/status.json — 200 — 1.2 KiB — 128 ms — h2https://www.python.org/box/supernav-python-about/www.python.org/box/supernav-python-... https://www.python.org/box/supernav-python-about/ — 200 — 654 B — 4 ms — h2https://www.python.org/box/supernav-python-downloads/www.python.org/box/supernav-python-... https://www.python.org/box/supernav-python-downloads/ — 200 — 698 B — 10 ms — h2https://www.python.org/box/supernav-python-documentation/www.python.org/box/supernav-python-... https://www.python.org/box/supernav-python-documentation/ — 200 — 390 B — 7 ms — h2https://www.python.org/box/supernav-python-community/www.python.org/box/supernav-python-... https://www.python.org/box/supernav-python-community/ — 200 — 705 B — 23 ms — h2https://www.python.org/box/supernav-python-success-stories/www.python.org/box/supernav-python-... https://www.python.org/box/supernav-python-success-stories/ — 200 — 501 B — 14 ms — h2https://www.python.org/box/supernav-python-blog/www.python.org/box/supernav-python-... https://www.python.org/box/supernav-python-blog/ — 200 — 503 B — 10 ms — h2https://www.python.org/box/supernav-python-events/www.python.org/box/supernav-python-... https://www.python.org/box/supernav-python-events/ — 200 — 223 B — 14 ms — h2https://www.python.org/static/favicon.icowww.python.org/static/favicon.ico https://www.python.org/static/favicon.ico — 200 — 14.9 KiB — 5 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 156ms · 49KB · CA$2/mo
www.python.org
Other
Optional
Execution 96ms
Transfer 49 KB
Monthly Cost CA$1/mo
ajax.googleapis.com
Other
Optional
Execution 60ms
Transfer 0 KB
Monthly Cost CA$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.

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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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